This article may help:
https://wiki.openstreetmap.org/w/index.php?title=GPX&oldid=1508044
Apparently a gpx file is an html file that's invalid unless the gps coordinates are time-stamped.

@erik-kueng The OpenStore word processor app uWriter enables you to store and edit html files. Check it out. I use this app and it works well. This is the app that @advocatux suggested above. Good luck.

@catalyst Just a thought: maybe BQ could replace the broken screen. On their support page, if you select 'broken screen', they offer to contact you. You can visit www.bq.com/uk/tablets. There you can find BQ Aquaris M10 Ubuntu Edition. Then you can use the support menu system to find 'broken screen'.
Good luck!

@advocatux I agree that the BQ Aquaris M10 is a great tablet for UT. I've looked around on ebay from time to time and never found a suitable alternative. I'm writing this reply on my M10 tablet and last night I watched UT Q&A 44 on it.

I have just installed this new webapp and it's great. I normally access my OpenOffice-365 email account via a Morph Browser bookmark and everything works as it should. Yesterday I tried the OpenOffice-365 Webapp and logged in to my account. It was really snappy and I like it. I tried it on my M10 tablet and my Nexus 4 and it performed well on both devices.
The only snag was a freeze which occurred when I opened the Junk Email folder and selected a message for deletion. This issue was repeatable on both my devices.

Ubuntu Touch on my M10 tablet is good for me. I use it for a minimum of 2 hours each day. My wife also uses it in preference to our laptop. Morph browser works fine. File Manager is really cool once you discover how to slide files right or left to reveal the hidden tools. System Settings and OpenStore are most reliable. You can roll your own webapps with Clickable or Webapp Creator. You can move files back and forth between your UT device and your Ubuntu laptop with WifiTransfer. Document Viewer and Sturm Reader handle pdfs smoothly.

I could go on. To close, I prefer Ubuntu Touch to Android. I wiped Android from my Nexus 4, installed UT and it's great.

In support of Android, many folk cite the availability of a plethora of apps. How many do you really need? Aren't many of them simply "shovelware"?

Oh, by the way the Community is knowledgeable and helpful.

I've noticed a somewhat obscure problem with this webapp. If I navigate to devices/available devices/BQm10HD for example, the page displays for a second or two and then blanks out.
This fault occurs if I am using my M10 tablet, but does not occur if I am using my Nexus 4. This is repeatable with both OTA 7 and release candidate.
If I visit the UBports website direct instead of via the webapp, the problem does not occur.
This seems to suggest that the UBports website, Morph browser and my M10 tablet are all OK. My conclusion is that there's an obscure gremlin in the weapp. Maybe someone could forward this information to Joerg Ulbricht. I couldn't find him on this site.

Here's a bit more stuff from the same stable that says it relates to ubuntu 16.04:

http://linuxiumcomau.blogspot.com/2018/03/

This should be more appropriate.

I just found some stuff that sounds relevant, but I'm afraid it's a bit over my head. Maybe it may mean more to someone else. See the following link:

http://linuxiumcomau.blogspot.com/2017/10/fixing-broken-hdmi-audio.html

Good luck!

I am disappointed that this bug does not appear to be a priority. My Blackberry Playbook had this feature working years ago. Surely this is a fundamental requirement if we wish to talk about convergence. The comment by @dobey on github implies that if it's not supported by pulse-audio, then it won't get fixed. Surely that's not good enough? What do others think?