unigram is very nice it is also as fast and secure as telegram but in unigram, I have found very nice UI and functionality. I love this application.
FluffyChat - Open. Nonprofit. Cute ?
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.
Telegram X - Meet Telegram X for iOS and Android – two new official apps that offer more speed, longer batter life and smooth animations.
Molly (Signal fork) - Molly is an independent Signal fork for Android
Plus Messenger - Free Android Messenger that uses Telegrams API.