Telegram Web App.
More info & source code here: https://github.com/zhukov/webogram
The Telegram web-client is a free, fast and secure way to enjoy most of Telegram's features right in your web-browser.
It is always synced with the Telegram app on your mobile device, which makes it a perfect tool for messaging and file sharing.
Our source code is open, so everyone can make a contribution.
Full stickers support
Multisearch box: instantly find chats, usernames and messages
Emoji autocomplete: e.g., type :kiss in the message field to see the list.
Added 'typing' notification in chats list
Online members counter in group headers
New material design
@username mentions in messages are clickable and open a conversation with the user
Forward messages to multiple recipients
New viewer for photos, videos, documents.
Added Native Client module: dramatically improved encryption speed; Download and upload speed is now as high as in native applications.
Added embedded Instagram, Vine, YouTube, Soundcloud, Vimeo links.
Jump to selected spot when playing back audio.
Added unsupported media playback warning.
Added global user search to contacts list.
Added switch to mobile version on window resize.
Search can now find public users by username
Most popular emoticons shown in 'recent' when empty
New languages: Spanish, German and Italian are now available
New custom-made audio player
Perfomance improvements and bugfixes
Log in codes may be received in other Telegram apps
Partner's online status updates automatically
Added support for non-english hashtags in messages
Fixed invalid scrollbar width bug
Added automatic country code detection