Firstgram Unofficial Telegram is an Android application developed by TH Team and is available for free. It adds extra features to the official Telegram app and has a variety of options for customization.

One of the main features is the separated tabs for chats, which includes users, groups, channels, bots, favorites, unread, admin/creator, and more. Additionally, there are options to customize the tabs, such as different sorting methods for chats. Users can also create custom groups of chats and save and restore categories.

Other features include multi-account support for up to 10 accounts, increased limits for pinned chats and favorite stickers, and the ability to forward messages without quoting and edit message/caption before forwarding. Users can also set photo quality before sending, show user's bio in chat, and start round video using the main camera, among many other options.

Overall, Firstgram Unofficial Telegram offers a wide range of features to enhance the user experience on the official Telegram app.