Fairphone’s Android doesn’t have a feature to answer your phone by holding it against your ear (but some competitors do). There are a lot of apps that add this functionality, but I had a hard time finding one that wasn’t filled to the brim with ads and/or spyware, so I made my own. It’s Open Source and tested primarily on the Fairphone 3. Hope it helps anyone!
Play Store: https://play.google.com/store/apps/details?id=me.hackerchick.raisetoanswer
F-Droid: Raise To Answer | F-Droid - Free and Open Source Android App Repository
Context: My dad got a Fairphone 3 and works as a painter and was worried of getting paint all over his phone screen, but I realize this app can help a lot of other people with several accessibility needs too, so I wanted to share it here.
Source code (if anyone wants to help out): https://github.com/TheLastProject/RaiseToAnswer