Ubuntu touch as PC?

DJac

@Yumi I understand what you mean.
But actualy, i found lomiri is not ready to be used as a PC (no desktop...). And UT don't already have some basics computers apps (libre office, vlc, firefox, scribus, gimp...). But in fact, phosh or kde mobile are not realy better.
i made a try with kde desktop (on postmarketOS) : more customizable, but pmOS is unstable on oneplus6.
So, the quest continue ! (why not mobian + kde desktop if possible?)

developerbayman

this is good news regarding lomri https://linuxiac.com/rhino-linux-2025-4-brings-lomiri-packages-and-updated-kernels/

rowanfields

Based on current state, Ubuntu Touch works better as a tech experiment than a daily PC replacement, mainly due to app support and desktop limitations. If you want to try anyway, Fairphone with external display support seems the least frustrating option for now.

oldbutndy

@Yumi
installed UT 2 days ago on 1+ Nord N10 (BE2026). [Note VoLTE worked, but NOT WiFi calling].
UT mentions 'Desktop Convergence', so I tried to see if my phone could reproduce my Linux Mint LibreOffice 'desktop experience'.
Easy to connect to WIRELESS external display (limited to 1080P), as long as that display runs Miracast (my LG TV's do).
Then I connected Acasis multiport USB-C hub, with PD charging, a wired keyboard, wired mouse, Gigabit ethernet adapter and USB-A Flash drive.
I installed LibreOffice via snap. (direct, no libertine required).
I opened a spreadsheet that had been created on main PC.
not as quick as main PC, but workable.
Image on TV was a bit 'wavy', moving top to bottom, as it refreshed, or something. (maybe 2.4Ghz WiFi interference also)
A phone model with WIRED external display capability probably fixes the 'wavy'.
I did NOT exhaustively test this (meaning the usability for lengthy spreadsheet changes).
It was just to see if it would work.
If you have a specific thing to try, let me know. I might be able to give a quick test.

mango

@oldbutndy and anyone:

Email, such as Thunderbird, with GPG-encryption, anyone tried that?
Firefox with addons? Anyone tried it?
Brave browser?
Linphone?

oldbutndy

@mango
I did find & install snap for Thunderbird a couple days ago. Installs, but not open (actually, a 'fuzzy box with a text bar at top appears, but nothing in fuzzy box). Then tried series of questions on Google AI 'reasoning model' via browser. It had a series of troubleshooting commands to type in to terminal. I did not follow through yet due to sharing the same display between UT phone and main PC doing the AI thread. Summary was AI estimate of required spending approximately 10 hours on configuration, IF using UT on a phone that had WIRED external monitor, USB Keyboard, mouse, etc. AI thought MANY more hours required if using a wireless external display.
I gave up on Thunderbird at that point.

Searched for snap for Linphone. found none.

Found snap for Signal. Installed. No account so it shows "failed to connect to server". So, it might work.

Firefox snap install process gave error: bad plugs or slots: kerberos-tickets (unknown interface "kerberos-tickets"). No icon installed on main screen.

Just installed Brave browser via snap. Installed with no errors, opens on wireless external display, and performs a web search, & display correctly. (5 second test. NOT comprehensive. but it opened & looked OK)

arubislander

@oldbutndy said in Ubuntu touch as PC?:

I did find & install snap for Thunderbird a couple days ago. Installs, but not open (actually, a 'fuzzy box with a text bar at top appears, but nothing in fuzzy box). Then tried series of questions on Google AI 'reasoning model' via browser. It had a series of troubleshooting commands to type in to terminal. I did not follow through yet due to sharing the same display between UT phone and main PC doing the AI thread. Summary was AI estimate of required spending approximately 10 hours on configuration, IF using UT on a phone that had WIRED external monitor, USB Keyboard, mouse, etc. AI thought MANY more hours required if using a wireless external display.
I gave up on Thunderbird at that point.

Please don't ask any AI how to get software to work on UT. Their training data does not contain the required info, and the correct steps cannot be extrapolated from whatever they were trained on, since sometimes the correct steps are either unknown, unfeasible for an end user, or simply don't exist yet.

Regarding the snaps from Mozilla (Firefox and Thunderbird, both) they are known not to work on UT as they are trying to use Wayland. They could be forced to use XWayland, but by then one might as well just install the click or the deb.

mango

Out of curiosity, I tried to get Thunderbird to behave properly on a Fairphone 4. Maybe it would be an idea to make a one-click-install that does all this for a newbie. openSUSE software catalogue has a one-click yaml installer script which sets everything up. Just an idea to make it user friendlier to get common software working out of the box so to say for a newbie to make it easier to adopt Ubuntu Touch.

Step 1: Installing Thunderbird inside a Libertine container

For those of you newbies wondering how to get Thunderbird Mail client working in desktop mode on Ubuntu Touch, this is one way that seems to work well. Thunderbird has so far not crashed a single time. However the Ubuntu Terminal app and nano crashed several times during this test. This markup was written in nano and copied to this forum spot to test the interoperability between different windows in desktop mode. Copy-paste functionality between windows seems to be a bit glitchy at the time of writing.

I messed around with settings until I got something that would work in desktop mode for Fairphone 4 running channel 24.04/daily.

Installing Thunderbird as DEB

Install Libertine Tweak Tool from Openstore.

Activate lirsh command with Libertine Tweak Tool.

Open a terminal window and type:

lirsh                                                                                  
fakeroot

We need command add-apt-repository command from package software-properties-common.

apt-get update                                                                         
apt-get upgrade                                                                        
apt-get install software-properties-common

On my Fairphone 4 I was also obliged to install package apt-utils that for some reason did not install correctly by itself.

apt-get install apt-utils

At this point it was possible to issue terminal command:

add-apt-repository ppa:mozillateam/ppa

cat <<EOF | tee /etc/apt/preferences.d/thunderbird-ppa
Package: thunderbird
Pin: release o=LP-PPA-mozillateam
Pin-Priority: 1001
Package: thunderbird
Pin: release o=Ubuntu
Pin-Priority: -1
EOF

apt-get update

apt-cache policy thunderbird

# apt install thunderbird
DEBIAN_FRONTEND="noninteractive" apt install thunderbird

exit # jump out of fakeroot

thunderbird --version

Now you can test if terminal command thunderbird launches something.

On my Fairphone 4, I saw a shaddow window but nothing more. I remembered reading that you have to force Xwayland in some way.

# lirsh
GDK_BACKEND=x11 thunderbird

On my Fairphone 4, the zoom factor is quite big. Let's try to lower the zoom.

One way to lower the zoom is to edit Libertine container noble file ~/.Xdefaults and adjust Xft.dpi: 120 from default value Xft.dpi: 197.

Exiting lirsh and re-entering lirsh should activate the new DPI setting.

Then re-launch thunderbird from command line and see if the zoom factor is better.

# lirsh
GDK_BACKEND=x11 thunderbird

Now the window looks a bit better with not such a large zoom factor in desktop mode.

The other way is to use a scaling factor directly before launching thunderbird.

Try this and see if the zoom factor is lower with standard setting Xft.dpi: 197.

# lirsh
GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 thunderbird

Once the scaling is okay for your eyes you can create a thunderbird-launcher.

# lirsh
mkdir -p ~/.local/bin
echo "GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 thunderbird" > ~/.local/bin/thunderbird-launcher
chmod +x ~/.local/bin/thunderbird-launcher

On my Fairphone 4, Libertine container noble folder ~/.local/bin
was not in my Libertine container variable $PATH:

# lirsh
echo $PATH

Editing Libertine container noble file .bashrc should do the trick.

Added the following lines at the end of .bashrc:

if [ -d ~/.local/bin ]; then
  export PATH="$HOME/.local/bin:$PATH"
fi

if [ -d ~/bin ]; then
  export PATH="$HOME/bin:$PATH"
fi

Exiting lirsh and re-entering lirsh should activate the new setting.

exit # jump out of lirsh
lirsh
echo $PATH

thunderbird-launcher

This command should open thunderbird inside lirsh with desired zoom.

Step 2: Making a Thunderbird Mail main menu item shortcut

Poking around with the settings, you may discover that there are actually two ways to launch Thunderbird Mail once it is installed.

Launching Thunderbird Mail from outside the Libertine container. This would require a separate launcher put in ~/.local/share/applications/thunderbird.desktop. User settings will be stored outside the Libertine container.
Launching from inside the Libertine container. This would require to edit the Libertine container's thunderbird.desktop file, which will sooner or later appear in Ubuntu Touch main menu. User settings will be stored inside the Libertine container.

For the purpose of illustration, I will do both approaches.

2a: Making a `thunderbird.desktop` outside Libertine container

It is not entierly clear to me what you have to do in order to trigger a main menu update after you have installed something in a Libertine container. Debian has a command update-menus which Ubuntu Touch does not have. Ususally, a reboot is the easiest way to update Ubuntu Touch main menu items. However, there should in theory be another way to refresh the main menu that is at this time unknown to me.

Now that this is working, let's try to create an Ubuntu Touch shortcut in the main menu. This can be done manually of course. In this example, I will piggy-back on what is already available.

Open another terminal tab (without lirsh environment).

mkdir -p ~/.local/share/applications

mkdir -p ~/.local/share/icons/hicolor/scalable/apps

wget -O ~/.local/share/icons/hicolor/scalable/apps/thunderbird.svg https://upload.wikimedia.org/wikipedia/commons/2/2f/Thunderbird_2023_icon.svg                                                                  

wget -O ~/.local/share/icons/hicolor/index.theme https://raw.githubusercontent.com/spk121/hicolor-icon-theme/refs/heads/master/index.theme 

sed -i "s|^Comment=.*$|Comment=Ubuntu Touch Icon Theme|g" ~/.local/share/icons/hicolor/index.theme

echo "Update icon caches (maybe obsolete)"

touch ~/.local/share/icons/hicolor

update-icon-caches ~/.local/share/icons/hicolor

# or

touch ~/.local/share/icons/hicolor

gtk-update-icon-cache ~/.local/share/icons/hicolor

echo
echo "We can re-use the thunderbird.desktop file that is in the Libertine container"

cp -v /userdata/user-data/phablet/.cache/libertine-container/noble/rootfs/usr/share/applications/thunderbird.desktop ~/.local/share/applications/thunderbird.desktop

echo
echo "Using scaling factor GDK_DPI_SCALE=1.2"
echo "to achieve similar scaling as with"
echo "Libertine container 'noble' GDK_DPI_SCALE=0.6"

sed -i "s|^Exec=.*$|Exec=bash -c \'GDK_DPI_SCALE=1.2 GDK_BACKEND=x11 /userdata/user-data/phablet/.cache/libertine-container/noble/rootfs/usr/bin/thunderbird\' %u|g" ~/.local/share/applications/thunderbird.desktop

echo
echo "Ubuntu Touch does not seem to find the thunderbird icon"
echo "by itself."
echo "    Icon=thunderbird"
echo "Icon has to be specified exactly with path to show in main menu."
echo "    Icon=/path/to/scalable/svg"

sed -i "s|^Icon=.*$|Icon=/home/phablet/.local/share/icons/hicolor/scalable/apps/thunderbird.svg|g" ~/.local/share/applications/thunderbird.desktop

echo
echo "Trigger main menu update"

mv ~/.local/share/applications/thunderbird.desktop ~/.local/share/applications/tmp.desktop

mv ~/.local/share/applications/tmp.desktop ~/.local/share/applications/thunderbird.desktop

echo
echo "You should now see Thunderbird Mail"
echo "in Ubuntu Touch main menu."
echo
echo "Done."

Now there should be a visible "Thunderbird Mail" launcher in Ubuntu Touch main menu.

Try hitting the "Super-key" (sometimes this key has four windows left of the space bar, sometimes it can have an apple design or command key) on your external wired PS-2 keyboard (or wireless keyboard)
and type thund which should be enough to make Thunderbird Mail laucher visible.

2b: Adjusting `thunderbird.desktop` inside Libertine container

Adjusting Libertine container thunderbird.desktop located at
~/.cache/libertine-container/noble/rootfs/usr/share/applications/thunderbird.desktop
could be done manually with terminal command:
nano ~/.cache/libertine-container/noble/rootfs/usr/share/applications/thunderbird.desktop

You may also install mousepad in the Libertine container to get a graphical editor. However, copy-paste does not seem to work between windows.

There are three lines starting with Exec= which needs to be adjusted to something like:

# Exec=thunderbird %u (original)
Exec=bash -c "GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 thunderbird %u"

# Exec=thunderbird -compose (original)
Exec=bash -c 'GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 thunderbird -compose'

# Exec=thunderbird -addressbook (original)
Exec=bash -c 'GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 thunderbird -addressbook'

This could be accomplished with using terminal command sed:

sed -i "s|^Exec=thunderbird %u$|Exec=bash -c \"GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 thunderbird %u\"|g" /home/phablet/.cache/libertine-container/noble/rootfs/usr/share/applications/thunderbird.desktop

sed -i "s|^Exec=thunderbird -compose$|Exec=bash -c 'GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 thunderbird -compose'|g" /home/phablet/.cache/libertine-container/noble/rootfs/usr/share/applications/thunderbird.desktop

sed -i "s|^Exec=thunderbird -addressbook$|Exec=bash -c 'GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 thunderbird -addressbook'|g" /home/phablet/.cache/libertine-container/noble/rootfs/usr/share/applications/thunderbird.desktop

Change the scaling factor GDK_DPI_SCALE to suit your eyes. Note that on my Fairphone 4 on channel 24.04/daily it seems to require a scaling factor less than 1.0 inside the Libertine container to scale things down. From outside the container, a scaling factor
larger than 1.0 had to be used to scale things up.

I am not sure about how to write the first launcher which has %u at the end. The %u in a .desktop file is a placeholder that allows the launcher to accept a single URL as an argument. A mailto link example is: <a href="mailto:someone@example.com">Send Email</a>. Ideally, such a link should be able to configure to open in Thunderbird Mail. Unfortunately I have not been able to discover how to configure it in Ubuntu Touch. There should be a mailto child in:

gsettings list-children org.gnome.desktop.default-applications

but it does not exist. If it would exist, maybe a command like:

gsettings set org.gnome.desktop.default-applications.mailto exec 'GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 thunderbird -compose'

would make it possible to open e-mail links in Thunderbird Mail.

Concluding thoughts

If all went well, you should now be able to set up any mail account and optionally create an OpenPGP encryption key to be used when sending encrypted email to somebody else whatever email provider they use, given that the recipient has a mail reader that can use your public OpenPGP key to decrypt the email message you sent them. If they also use Thunderbird Mail client, OpenPGP encryption will work in the same way on their system. Several other mail clients, such as Evolution Mail client support OpenPGP encryption in a similar way but it might require more to configure it than in Thunderbird, which is more user friendly in this particular aspect. Of course, the email meta data will most probably not be encrypted. If you wish to avoid email metadata you might want to use tuta-mail or proton-mail or any other mail that never leaves the email provider. If somebody knows how to get a mail reader for tuta-mail or proton-mail to Ubuntu Touch, I am sure some users would appreciate that.

Having Morph browser open with several tabs and Thunderbird Mail open at the same time uses 3.1-5.9Gi RAM memory, reports terminal command free -h.

oldbutndy

@mango
Wow !
Thank you for that effort !
I like your one-click-install idea ...
Now, to access Proton mail via Thunderbird, just need to install Proton Mail Bridge on host Linux PC, and configure phone to access that ?
or
compile Proton Mail Bridge for ARM ?

mango

Out of curiosity, since I managed to get Thunderbird to behave properly on a Fairphone 4... maybe it would be an idea to make a similar guide for Firefox web browser.

Step 1: Installing Firefox inside a Libertine container

For those of you newbies wondering how to get Firefox web browser working in desktop mode on Ubuntu Touch, this is one way that seems to work well. Firefox has so far crashed one time only.

This markup was written in nano and mousepad. Copy-paste functionality between windows seems to be non-existent between Firefox and other windows at the time of writing. The only way to copy this markup was to cat markdown-text.md in a terminal and manually copy the lines from terminal with right-click copy, and paste it in this forum.

I messed around with settings until I got something that would work in desktop mode for Fairphone 4 running channel 24.04/daily.

Installing Firefox as DEB

Install Libertine Tweak Tool from Openstore.

Activate lirsh command with Libertine Tweak Tool.

Open a terminal window and type:

lirsh                                                                                  
fakeroot

At this point it is possible to issue terminal commands:

install -d -m 0755 /etc/apt/keyrings

wget -q https://packages.mozilla.org/apt/repo-signing-key.gpg -O- | tee /etc/apt/keyrings/packages.mozilla.org.asc > /dev/null

echo "deb [signed-by=/etc/apt/keyrings/packages.mozilla.org.asc] https://packages.mozilla.org/apt mozilla main" | sudo tee -a /etc/apt/sources.list.d/mozilla.list > /dev/null

echo '
Package: *
Pin: origin packages.mozilla.org
Pin-Priority: 1000
' | tee /etc/apt/preferences.d/mozilla

apt-get update 

# If you want to update the whole Libertine container
apt-get upgrade --fix-missing

apt-cache policy firefox

apt-get install firefox

exit # jump out of fakeroot

firefox --version

# To install a different language pack, execute:
# lirsh

apt-cache search firefox-l10n

# to get the list of all available language packages.
#
# Install the language pack of your choice like:

fakeroot

apt-get install firefox-l10n-es-es # Spanish

# or

apt-get install firefox-l10n-de # German

# or

apt-get install firefox-l10n-fr # French

You may now see Firefox in Ubuntu Touch main menu, or not. One way to trigger a main menu update is to create an update or a .desktop file in one of the catalogues that Ubuntu Touch is monitoring. Try these lines one at a time, to see if the launcher appears, in a fresh terminal tab:

if [ -d /home/phablet/.local/share/icons/hicolor ]; then
  touch /home/phablet/.local/share/icons/hicolor
else
  mkdir -p /home/phablet/.local/share/icons/hicolor/scalable/apps
  wget -O /home/phablet/.local/share/icons/hicolor/index.theme https://github.com/matthewbauer/appstream-generator/raw/refs/heads/master/data/hicolor-theme-index.theme
fi

A minimal index.theme can also be made like this:

cat <<EOF > /home/phablet/.local/share/icons/hicolor/index.theme
[Icon Theme]
Name=Hicolor
Comment=Ubuntu Touch fallback icon theme
Hidden=true
Directories=scalable/apps

[scalable/apps]
MinSize=1
Size=128
MaxSize=256                                                                            
Context=Applications                                                                   
Type=Scalable
EOF

If Firefox still does not show up in Ubuntu Touch main menu, you can try to make a change in folder /home/phablet/.local/share/applications:

cp -v /home/phablet/.cache/libertine-container/noble/rootfs/usr/share/applications/firefox.desktop /home/phablet/.local/share/applications/.

sleep 3

rm -v /home/phablet/.local/share/applications/firefox.desktop

Try hitting the "Super-key" (sometimes this key has four windows left of the space bar) and type firef which should be enough to make Firefox laucher visible.

Now you can test if terminal command launches something.

# lirsh
GDK_BACKEND=x11 firefox

On my Fairphone 4, the zoom factor is quite big. Let's try to lower the zoom.

One way to lower the zoom is to edit Libertine container noble file ~/.Xdefaults and adjust Xft.dpi: 120 from default value Xft.dpi: 197.

Exiting lirsh and re-entering lirsh should activate the new DPI setting.

Then re-launch firefox from command line and see if the zoom factor is better.

# lirsh
GDK_BACKEND=x11 firefox

Now the window looks a bit better with not such a large zoom factor in desktop mode.

The other way is to use a scaling factor directly before launching firefox.

Try this and see if the zoom factor is lower with standard setting Xft.dpi: 197.

# lirsh
GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 firefox

Once the scaling is okay for your eyes you can create a firefox-launcher.

# lirsh
mkdir -p ~/.local/bin
echo "GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 firefox" > ~/.local/bin/firefox-launcher
chmod +x ~/.local/bin/firefox-launcher

On my Fairphone 4, Libertine container noble folder ~/.local/bin
was not in my Libertine container variable $PATH:

# lirsh
echo $PATH

Editing Libertine container noble file ~/.bashrc should do the trick. The full path is:

/home/phablet/.cache/libertine-container/noble/rootfs/home/phablet/.bashrc

You can edit this file both from outside the Libertine container noble as well as from inside the Libertine container.

Added the following lines at the end of the Libertine container ~/.bashrc:

if [ -d ~/.local/bin ]; then
  export PATH="$HOME/.local/bin:$PATH"
fi

if [ -d ~/bin ]; then
  export PATH="$HOME/bin:$PATH"
fi

Exiting lirsh and re-entering lirsh should activate the new setting.

exit # jump out of lirsh
lirsh
echo $PATH

firefox-launcher

This command should open firefox inside lirsh with desired zoom.

Step 2: Making a Firefox main menu item shortcut

Poking around with the settings, you may discover that there are actually two ways to launch Firefox once it is installed.

Launching Firefox from outside the Libertine container. This would require a separate launcher put in ~/.local/share/applications/firefox.desktop. User settings will be stored outside the Libertine container.
Launching from inside the Libertine container. This would require to edit the Libertine container's firefox.desktop file, which will sooner or later appear in Ubuntu Touch main menu. User settings will be stored inside the Libertine container.

For the purpose of illustration, I will do both approaches.

2a: Making a `firefox.desktop` outside Libertine container

It is not entierly clear to me what you have to do in order to trigger a main menu update after you have installed something in a Libertine container. Debian has a command update-menus which Ubuntu Touch does not have. Ususally, a reboot is the easiest way to update Ubuntu Touch main menu items. However, there should in theory be another way to refresh the main menu that is at this time unknown to me.

Now that this is working, let's try to create an Ubuntu Touch shortcut in the main menu. This can be done manually of course. In this example, I will piggy-back on what is already available.

Open another terminal tab (without lirsh environment).

mkdir -p ~/.local/share/applications

mkdir -p ~/.local/share/icons/hicolor/scalable/apps

wget -O ~/.local/share/icons/hicolor/scalable/apps/firefox.svg https://upload.wikimedia.org/wikipedia/commons/a/a0/Firefox_logo%2C_2019.svg

wget -O ~/.local/share/icons/hicolor/index.theme https://raw.githubusercontent.com/spk121/hicolor-icon-theme/refs/heads/master/index.theme 

sed -i "s|^Comment=.*$|Comment=Ubuntu Touch Icon Theme|g" ~/.local/share/icons/hicolor/index.theme

echo "Update icon caches (maybe obsolete)"

touch ~/.local/share/icons/hicolor

update-icon-caches ~/.local/share/icons/hicolor

# or

touch ~/.local/share/icons/hicolor

gtk-update-icon-cache ~/.local/share/icons/hicolor

echo
echo "We can re-use the firefox.desktop file that is in the Libertine container"

cp -v /userdata/user-data/phablet/.cache/libertine-container/noble/rootfs/usr/share/applications/firefox.desktop ~/.local/share/applications/firefox.desktop

echo
echo "Using scaling factor GDK_DPI_SCALE=1.2"
echo "to achieve similar scaling as with"
echo "Libertine container 'noble' GDK_DPI_SCALE=0.6"

sed -i "s|^Exec=.*$|Exec=bash -c \'GDK_DPI_SCALE=1.2 GDK_BACKEND=x11 /userdata/user-data/phablet/.cache/libertine-container/noble/rootfs/usr/bin/firefox\' %u|g" ~/.local/share/applications/firefox.desktop

echo
echo "Ubuntu Touch does not seem to find the firefox icon"
echo "by itself."
echo "    Icon=firefox"
echo "Icon has to be specified exactly with path to show in main menu."
echo "    Icon=/path/to/scalable/svg"

sed -i "s|^Icon=.*$|Icon=/home/phablet/.local/share/icons/hicolor/scalable/apps/firefox.svg|g" ~/.local/share/applications/firefox.desktop

echo
echo "Trigger main menu update"

mv ~/.local/share/applications/firefox.desktop ~/.local/share/applications/tmp.desktop

mv ~/.local/share/applications/tmp.desktop ~/.local/share/applications/firefox.desktop

echo
echo "You should now see Firefox"
echo "in Ubuntu Touch main menu."
echo
echo "Done."

Now there should be a visible "Firefox" launcher in Ubuntu Touch main menu.

Try hitting the "Super-key" (sometimes this key has four windows left of the space bar, sometimes it can have an apple design or command key) on your external wired PS-2 keyboard (or wireless keyboard) and type firef which should be enough to make Firefox laucher visible.

2b: Adjusting `firefox.desktop` inside Libertine container

Adjusting Libertine container firefox.desktop located at
/home/phablet/.cache/libertine-container/noble/rootfs/usr/share/applications/firefox.desktop
could be done manually with terminal command:
nano ~/.cache/libertine-container/noble/rootfs/usr/share/applications/firefox.desktop

You may also install mousepad in the Libertine container to get a graphical editor. However, copy-paste does not seem to work between windows.

There are four lines starting with Exec=:

Exec=firefox %u
Exec=firefox --new-window %u
Exec=firefox --private-window %u
Exec=firefox --ProfileManager

These four lines starting with Exec= need to be adjusted to something like:

Exec=bash -c "GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 firefox %u"
Exec=bash -c "GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 firefox --new-window %u"
Exec=bash -c "GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 firefox --private-window %u"
Exec=bash -c 'GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 firefox --ProfileManager'

This could be accomplished with using terminal command sed:

sed -i "s|^Exec=firefox %u$|Exec=bash -c \"GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 firefox %u\"|g" /home/phablet/.cache/libertine-container/noble/rootfs/usr/share/applications/firefox.desktop

sed -i "s|^Exec=firefox --new-window %u$|Exec=bash -c \"GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 firefox --new-window %u\"|g" /home/phablet/.cache/libertine-container/noble/rootfs/usr/share/applications/firefox.desktop

sed -i "s|^Exec=firefox --private-window %u$|Exec=bash -c \"GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 firefox --private-window %u\"|g" /home/phablet/.cache/libertine-container/noble/rootfs/usr/share/applications/firefox.desktop

sed -i "s|^Exec=firefox --ProfileManager$|Exec=bash -c 'GDK_DPI_SCALE=0.6 GDK_BACKEND=x11 firefox --ProfileManager'|g" /home/phablet/.cache/libertine-container/noble/rootfs/usr/share/applications/firefox.desktop

Change the scaling factor GDK_DPI_SCALE to suit your eyes. Note that on my Fairphone 4 on channel 24.04/daily it seems to require a scaling factor less than 1.0 inside the Libertine container to scale things down. From outside the container, a scaling factor larger than 1.0 had to be used to scale things up.

Testing

If all went well, you should now be able to set up Firefox with any extensions you prefer.

Sample of extensions that seem to do what they are supposed to do to a great extent:

uBlock Origin
NoScript
Privacy Badger
Cookie Autodelete
I still don't care about cookies
Video DownloadHelper (not possible to select other video format than default). Remark: When opening a downloaded media clip with Thunar file manager, Lomiri crashed and closed all open apps.

Observations

The mouse pointer becomes huge when hovering Firefox. There should be a way to make the mouse pointer smaller.
Copy-paste does not work well. Not possible to copy and paste from Firefox to mousepad nor into nano. Clipboard looks full at the beginning and clicking on paste greys out clipboard while nothing is pasted.
https://duck.ai works (does not seem to work properly in Morph browser). However, you cannot copy-paste the answers.

Having Firefox browser open with several tabs at the same time uses 3.7Gi RAM memory, reports terminal command free -h.