This app was mentioned in 6 comments, with an average of 1.00 upvote
I'm not able to answer your first question unfortunately, but #2 is easy: check out one of the many apps available on the Play Store. Just search for "odt" or "LibreOffice".
Being the author of one of those apps, I'd highly recommend to check out this one: https://play.google.com/store/apps/details?id=at.tomtasche.reader
(Also available on iOS in case that is your thing: https://opendocument.app/)
I'd recommend checking out one of the many alternatives available on the Play Store. Only few of them are able to replicate the exact same functionalities provided by LibreOffice (because LibreOffice is huge!), but they come with the benefit of being much more lightweight, fast and easy to use.
I might be biased being the author of the app, but OpenDocument Reader is good if you ask me: https://opendocument.app/ https://play.google.com/store/apps/details?id=at.tomtasche.reader
We're sincerely interested in improving the app based on our users' feedback. Let me know if you need help.
For me, it would be good if I could edit the only ods file (in which I keep logging my spendings and is stored in dropbox) on my tablet. The only app which claims to be able to edit it (OpenDocument Reader), only lets modify cells which has value. You can't even select the empty ones!
I guess I'll try to convert it to xls, and see if Polaris Office is any better...
For me, it would be good if I could edit the only ods file (in which I keep logging my spendings and is stored in dropbox) on my tablet. The only app which claims to be able to edit it (OpenDocument Reader), only lets modify cells which has value. You can't even select the empty ones!
I guess I'll try to convert it to xls, and see if Polaris Office is any better...
Is a nice libre office file reader
Found this. Never tried it.
https://play.google.com/store/apps/details?id=at.tomtasche.reader