copy from https://github.com/ms-iot/samples/tree/develop/BluetoothGATT/CS
nRF UART app can be used to connect to Bluetooth® Smart devices running a custom Nordic Semiconductor UART service. When connected, the app can send and receive ASCII and UTF-8 text strings.
eclipse/ has the examples that eclipse can load (no longer updated). Otherwise, everything uses android studio.
The DFU Library for iOS 8+ adds the DFU feature to the iOS project. It is written in Swift 2.1 but is compatible with Objective-C.
A Swift implementation of Ray Wenderlich's OpenGL ES 2.0 Tutorial - Part 1.