Install instructions and user guide for the Crazyflie Android client
Screenshot:

Installation
Hardware requirements:
- Crazyflie 1.0 or Crazyflie 2.X
 - Crazyradio dongle (required for Crazyflie 1.0, optional for crazyflie 2.X
 - USB On-the-go (OTG) cable (aka. USB Host cable) with Micro USB to USB
    
- e.g. from Amazon
 
 - Android device with Android version 4.0 (API Level 14) or higher
 - Android device with support for Bluetooth LE and Android version 4.4+ (required when connecting to Crazyflie 2.X over Bluetooth LE)
 - Optional: PS3 controller (or compatible)
 
Downloading the app
There is now an official version in the Google Play Store: https://play.google.com/store/apps/details?id=se.bitcraze.crazyfliecontrol2