Telegram Messenger is an instant messaging app that uses phone numbers (or possibly usernames) to connect users. With Telegram, users can send messages, images, videos, audios and any other type of file. The instant messaging app category is a hotly contested area, and some of Telegram's competitors include WhatsApp, Google Hangout, BBM, WeChat, Facebook Messenger, and LINE (among many others).
Telegram Messenger was launched in 2013, created and financially backed by Russian billionaire brothers Pavel and Nikolai Durov, the founders of Russian social networking site VKontakte who wanted to build a communication system that Russian security agencies could not access. /P>
It is built on the open source MTProto protocol. Telegram prides itself on being fast, reliable, and available on (and accessible from) multiple devices at the same time. It also uses a distributed server architecture with multiple data centers spread across different jurisdictions around the world.
Telegram also promised never to sell advertisements, will not accept outside investment and cannot be sold. Since the protocol is open source, independent developers are allowed (and encouraged) to build third-party clients on the platform.
Telegram is available for Android, iPhone, Windows Phone, Linux, Windows, OSX and via web.
To start using Telegram, you need to register with a phone number. The phone number then becomes your identity on Telegram. Additionally, you can set a username through which other users can connect and chat without having access to the phone number linked to the username. Usernames are optional and can be removed at any time by simply registering an empty username.
For secret chats, a self-destruct timer can also be set on messages. This must be set before sending the message. The timer starts when the recipient views the message and when it runs out, the message is deleted from both devices. Photos sent with a timer of less than a minute can only be viewed by holding a finger on them, and Telegram helpfully notifies the sender if a screenshot is taken.
Users can create groups of up to 200 users and can send broadcast messages to up to 100 contacts. The difference between groups and broadcasts is that in a broadcast message the recipients do not know each other, while in a group all participants see all other participants.
Telegram Messenger is a major challenger for the instant messaging app crown. It has so many goodies, including speed of message delivery, focus on security and privacy, lack of ads, and all the bells and whistles expected (and more) from a modern messenger.