I noticed “The Ultimate FOSS Guide for Android” was very out of date and thought I’d try to make a new version with more current suggestions. But after a while I realized most of the time I was just copying off PrivacyGuides.org which has a pretty robust set of FOSS offerings with an unsurprising focus on privacy.
There are still some things it doesn’t cover like Android launchers and keyboards, but we could have an additional sidebar post with more a la carte suggestions.
Thoughts? 
openboard or heliboard are FOSS and good on that front. they fork gboard and behave similarly.
trebuchet is available on the play store iirc and is good toono its not