https://github.com/niedev/BluetoothCommunicator should be included because it is the first library in this collection for Bluetooth LE based communication between android phones.

Once integrated into an app it allows you to find, connect, send and receive text or raw data with other devices that use the same app.

It is the first good working example of Bluetooth LE communication between Android phones, for anyone who wants to look into the code.

It automatically implements (they are active by default) reconnection in case of temporary connection loss, reliable message sending, splitting and rebuilding of long messages, the sending of messages with a queue in order to always send the messages even in case of connection problems (they will be sent as soon as the connection is restored) and in the right order.

Lastly, it works better than Google Nearby Connections and Wifi Direct APIs of Android, according to my tests.