The instant messaging app created by the founder of the social networking site VK continues to grow, although it still has a long road ahead until it can challenge Facebook Messenger or WhatsApp. Telegram Messenger was used by 200 million people within the 30 days for the first time — as many users as the population of the sixth-largest country in the world.
https://www.notebookcheck.net/Telegram-hits-200-million-active-monthly-users.291294.0.html
Absolutely no reason to use Telegram over Signal. The former is nowhere near as secure and private as advertised.
Yeah, I heard about Signal in a YouTube video by Anonymous. Still have to try that one. On the other hand, I have a few buddies on Telegram already and I started using it on Firefox OS, being probably the only program in this niche that bothered to have a version for that platform.