For some of the following phones....Motorola, LG, HTC, Sony, the "Pair" request during Discover device appears as an Android notification.  

Open the notification, tap Pair. This should establish the Bluetooth connection. 

 If issues persist and the app requests to pair multiple times, quit the app (swipe it off your phone) and open the app again.  Go to Settings, Device Settings and repeat the Discover process.  Choose Pair in the Android notification again.