Edit: the app seems to be pretty old, I like the Writer editing more (it works) but for other things, CollaboraOffice is way better.
Has anyone tried that on a tablet? The phone UI has like no features
Currently it is a “viewer” (renderer with usable UI) and editing features are experimental.
They only release their APK to Google Play for whatever reason, but you can use F-Droid to get it
Bugs can normally be reported to their bugtracker and you can join their forum for more community support!
Downside: the editing features are VERY rudimentary, while the app is only about 50MB (⅕) smaller than Collabora-Office, which has better features overall.
I installed it from F-Droid back on December last year. This post is kinda of inaccurate.