FluffyChat - Open. Nonprofit. Cute ?
Molly (Signal fork) - Molly is an independent Signal fork for Android
Olvid - The most secure messaging app in the world.
Mi Airit - Mi Airit a chat app that helps you communicate messages to the right people without receiving unwanted responses or reactions.
aTalk - An encrypted instant messaging with video call and GPS features for android.
NYNJA - NYNJA is an all-in-one communications tool that comes with real-time support to share files and chat.