You are right, blog texts are not translated in Weblate.
As explained in this issue by Jan Sprinz, it would be a lot of work for the UBports project (knowing that a vast majority of blog posts are links to Q&A videos and audiocasts).
They prefer to let this task to loco teams.
Maybe you can contribute to the only French website I know?
I think these people are available through Telegram.
Have you heard about Imaginario?
You can translate it here or directly in Launchpad.
Two great apps to translate: Webapp-creator and uAdBlock
@Flohack OK it works now, thank you for your feed-back
Cool, thanks!
Now 100% translated in French.
Where can we access to the source code though?
I would like to report the following bug but do not know how:
"A IMAP server configuration was found for you domain." (string 22)
"A IMAP server configuration was found for youR domain." instead?
With a little delay, thank you @advocatux for your kind answer.
Now the System Settings app is fully translated in French 
However, when I try to propose another translation for any string of the UBports app, I get this message:
IOError at /translate/ubports/ubports-app/fr/
[Errno 13] Permission denied: u'/opt/weblate/data/vcs/ubports/ubports-app/po/fr.po'
Anyone with the same issue?
If it is really a bug, where could I report it?
It seems the translations for the System Settings app have been recently updated in https://ubpweblate.tnvcomp.com/projects/ubports/system-settings/fr/
But I cannot access to Weblate.
Am I the only one to see this message?
DisallowedHost at /projects/ubports/system-settings/fr/
Invalid HTTP_HOST header: 'ubpweblate.tnvcomp.com'. You may need to add u'ubpweblate.tnvcomp.com' to ALLOWED_HOSTS
Hello, you can count on me for the French translation.
Good work everyone!