It should work on any android, but grapheneOS is the prime target.
Discussion
Speak button is disabled, on graphene
Do you have a text to speech engine installed?
We recommend SherpaTTS, get it on nostr:nprofile1qqs83nn04fezvsu89p8xg7axjwye2u67errat3dx2um725fs7qnrqlgzqtdq0
Didn't have it the first time. After installing sherpatts from zapstore, it's still not speaking
Open Sherpa and download an engine, we recommend en_GB-southern_english_female-medium in the piper models.