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.
qTox - A Qt graphical user interface for Tox.
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Tox - Send messages, files, create groups and make Tox to Tox audio and video calls. Securely.
Telegram X - Meet Telegram X for iOS and Android – two new official apps that offer more speed, longer batter life and smooth animations.
uTox - µTox is the lightweight client with minimal dependencies; it not only looks pretty, it runs...
Webogram - Webogram is an unofficial Telegram web app.