Fastgram is an informal with proprietary proxies running under the Api Telegram.

🔆 FastGram Features:
👻 Ghost Mode
🙇 Show online contacts / two way contacts
📆 Support for Persian calendar
Ⓜ️ proxies proprietary Mtproto ⭐️

💎 Other special features:

✅ Advanced Forward
✅ Forward without quotes
✅ Channel helper
✅ Beautiful Noodle Profile
✅ Customize the template
✅ View deleted messages ⭐️
✅ View edited messages ⭐️
✅ Profile of cheer ⭐️
✅ Radar Dating ⭐️
✅ Change the sound ⭐️
✅ Telegram Manager
✅ Finder
✅ Ability to change fonts
✅ Ad Blocker (App Blocker)
✅ Hiding and locking chats
✅ Infinite categories (managed)
✅ Use multiple concurrent accounts
✅ The ability to change the server in the event of a slowdown
✅ Voice call
✅ vacuum cleaner
✅ Special support

In terms of security there is no difference between the Fast Gram and the main telegram and the FastGram connects directly to the main telegram servers.