Telegram is just amazing, it was created by a Russian programmer, his name is Pavel Durov, he is the creater of the most famous and the biggest social network in Russia that is called : vk.com ( in russian vkontakte or in contact )
I've known about telegram for a few years, but just this year one of my business partners explained to me how great it is for use in managing your business. So I just installed it and I am using it now to organize my contacts a better way and to be in touch with them, it has groups, channels and even robots that do a lot of interesting things like collecting information, or organizing all information that you have in one robot called bot !
For example there is one bot that helps people to trade bitcoin and some other coins without using any website but connecting you to real people online that want to exchange right now !
You can find me there as @cnycik
I will introduce you to more things to use there, it's international, big and simple !
Also now I am creating a new community to earn money online.
And there are also other good bots that you can google, it's useful for everything, better than any messanger I've ever known.