Some experts have also pointed out that Telegram’s services aren’t that secure and protected, as its end-to-end encryption is not set up by default. So, users have to turn that on manually. Telegram still offers its users the option to share files, set messages to self-destruct with a destruct timer and chat in Supergroups of up to 200,000 users. It can also synchronize messages across all your devices, and it all costs absolutely nothing to users. App users can log in on multiple devices at the same time and can also receive messages on all devices.
Here you can download Telegram messenger, Telegram