This document discusses using beacons and Bluetooth Low Energy (BLE) with Android applications. It begins with an overview of beacons, how they work using BLE signals, and their importance. It then covers communicating between Android and beacons using BLE, relevant Android permissions and APIs, finding and connecting to BLE devices. Example code is provided for reading BLE attributes. It also discusses Android beacon libraries, building a sample app, and concludes with discussing a case study of an employee tracking app and some technical pitfalls.