I’m a big Matrix fan, because of their focus on bridges, but unforunately they do not have a function yet where you can register and login with your phone nr + finding contacts via your contacts list. THis is a must for mainstream users (moms and dads), imo
I just found this: Quicksy https://www.f-droid.org/en/packages/im.quicksy.client/
To my knowledge, this is the only messaging app around now that allows for registering and logging in with your phone nr + finding contacts via contacts list + that is open-source and federated. Does anyone know any others?