Telegram FOSS app
Telegram FOSS is Internet tool that is open source under the GPL-2.0-or-later license. *Warning:* Creating new accounts in the FOSS version not possible anymore, you have to create an account in the official build and then login to the FOSS.Client for the Telegram messaging platform.
Chat with friends, start group chats and share all kinds of content. All of your messages and conversations are stored in Telegram's cloud.
The messaging platform is aimed at mobile devices, but desktop and web clients exist as well.
Several proprietary parts were removed from the original Telegram client, including Google Play Services for the location services, HockeySDK for self-updates and push notifications through Google Cloud Messaging. Location sharing functionality is restored using OpenStreetMap.
Anti-Feature: Non-Free Network, since the servers run proprietary software.
The official source code of the app contains binary blobs, so this tracks a fork which builds those from source. Hence, versions might become available with a certain lag.