Bitchat
Twitter co-founder Jack Dorsey has a new side project. Dubbed Bitchat, it's a secure mesh chat program that works over Bluetooth, and thus doesn't require an Internet connection. In a similar fashion to old-school chat service IRC, rooms can be created using hashtags for specific topics, and password-protected if desired; like Twitter, users are given @nicknames. All messages are end-to-end encrypted, and can relay through peers for a range of over 300 meters. An early build was released via Apple's development tool Testflight, but has hit its user limit — but intrepid users can download the source code from GitHub and build the app themselves.