SchildiChat

SchildiChat is a client for the matrix protocol, based on the Element app. The matrix protocol is a decentralized approach to modern messaging, allowing for end-to-end encryption, shared message history across multiple devices, and more.
By building on Element, SchildiChat inherits all features of one of the most complete and feature-rich Matrix-clients currently available.
On top, SchildiChat adds a different design and various extra tweaks, customization options, and additional community features.

SchildiChat is open source: https://github.com/SchildiChat/SchildiChat-android
More information about the Matrix protocol: https://matrix.org/