Cryptpad Office
For spreadsheets, rich text documents, presentations and other types of files on which you want to collaborate with others, check out Cryptpad at https://office.ravergram.club/.
The spreadsheets in Cryptpad do not render well on some mobile devices. If you or others with whom you will collaborate expect to use a mobile device, I setup Ethercalc at https://pad.ravergram.club/ for you to use.
This is a private alternative to Google docs and Office 365. It is end to end encrypted which means that I cannot see anything nor even change your password. So use a password manager and don't lose your password!
If you create an account, you will see that you only have a small amount of space in the drive. If you want more space, just click your profile icon in the upper right hand corner of the screen and click [Support] to tell me how much space you want.