Telegram is free and open source messaging app available for all major platforms including Linux. Telegram Desktop which is a desktop client of Telegram recently released newer version Telegram 0.9.18 with some improvements and bug fixes. You can easily install Telegram Desktop on your Linux machine.
Telegram Desktop 0.9.18 only released with some improvements and bug fixes. They only mentioned that this release contains some bug fixes and improvements not even mentioned what was fixed and improved. Well, here is how it looks.
You can simply download Telegram desktop client from the official website and the website auto detect your system.