Flexbot is the control app for the same called drone project. Easiest way to fly your tiny drone. It connects to Flexbot drone via BLE 4.0, has the remote control ability in 25 meters distance.
You can see the detail of Flexbot here www.flexbot.cc/wiki.
BTW: There are some system bugs about BLE 4.0 on Android 4.3, so suggest updating your device to Android 4.4+.
If your Android 4.3 smart device can't connect to Flexbot, please restart the smart device and try again.