I tried Collabora on a Galaxy Droid and it was such a massively buggy disappointment: in a .ODS file, I couldn't backspace more than once; I could only delete one character at a time. I had to enter another character or move the cursor or do something else before it would take another backspace. I don't understand how this app has as high reviews as it does, or no one has used its spreadsheet editor.
I so far can't get away from Google Drive because tables are absolutely critical to my work... Any ideas to help de-Google would be deeply appreciated!
Update: The search continues, as ONLYOFFICE did not work out either and similarly had file-editing problems. For now, I've resorted to .TXTs...