Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Trillian - Trillian is a decentralized and federated instant messaging platform that lets your whole company send private and group messages, keep tabs on what co-workers are doing, share files, and much more.
Telegram X - Meet Telegram X for iOS and Android – two new official apps that offer more speed, longer batter life and smooth animations.
Plus Messenger - Free Android Messenger that uses Telegrams API.
Adium - Adium is a free instant messaging application for Mac OS X that can connect to AIM, MSN, Jabber, Yahoo, and more.
Unigram - The Telegram client for the Windows 10 platform, built by the community for the community.