I have ditched the #protonmail Android app. It was the last non-FOSS one on my phone. It complained all times about Google Services I don't have (LineageOS). And now I discovered that the said app uploads all the contacts I mail to PM’s servers where they’re kept in an unencrypted form. Not to mention all the bugs—since 2 versions or so the app crashes when there's no Internet connection. And new versions introduce only regressions; no changelog, no new functions. Just misery.
For people who care about, support, or build Free, Libre, and Open Source Software (FLOSS).