According to the description, this app is classified as private. More info here -
https://play.google.com/store/apps/details?id=com.tasks.android
Note: Collabora Office doesn't seem to have a check box feature. I also tried CryptPad twice, but it kept giving me an invalid username/password error (no misspellings or anything). I basically want to use a simple checklist app with collaboration features (shared lists with family, etc).
By the way, I've attempted to use Proton Docs before. It's too glitchy (cursor moves all over the place while using either default keyboard or Gboard/SwiftKey).