Telegram is a social messaging app. This app have many features and functions. User interface is very good. Layout and design is good. Easy to in use. App available on play store. And light weight app.
Telegram is open source and have some unique special features such as BOT features.
Bot is useful for Developers and IoT Developers.
Only one disadvantage of this app , this app not more popular like another social messaging app. So you cant find all friends on this app.
Overall this app is useful and provide great service.