Telegram is a cloud-based mobile and desktop messaging app with a focus on security and speed.
Mobile Apps:
- Get Telegram for iPhone and iPad
- Get Telegram for Android
- Get Telegram for Windows Phone
- Get Telegram for Firefox OS
Desktop and Web Apps:
- Get Telegram for Windows
- Get Telegram for Windows (Portable)
- Get Telegram for OS X
- Get Telegram for Linux 64 bit
- Get Telegram for Linux 32 bit
- Get Telegram Web (Online)
- Get Telegram Chrome
Source:
https://telegram.org/apps