Telegram is a messaging app with a focus on speed and security, it’s super
fast, simple and free. You can use Telegram on all your devices at the same
time — your messages sync seamlessly across any number of your phones,
tablets or computers.
With Telegram, you can send messages, photos, videos and files of any type
(doc, zip, mp3, etc), as well as create groups for up to 50,000 people or
channels for broadcasting to unlimited audiences. You can write to your
phone contacts and find people by their usernames. As a result, Telegram is
like SMS and email combined — and can take care of all your personal or
business messaging needs.