I have it's not the app it's the pairing of the Bluetooth adaptor. Go into your phones / pad Bluetooth setting on your phone and unpair the adaptor, Then open the lite app, making sure you select the right one, which should be the low power Bluetooth adaptor.
In the app select receive and you should get the Bluetooth start icon, press the start icon, you will then see searching for BT plus, on the adaptor press the button for around a second and the green start light should flash. The app should then show it's searching for the adaptor, then connected to the adaptor. The next message the app will show is waiting for down load of results (or similar). The app should then show it's down loading results. followed by the green tick.
If this does not work go back into phones Bluetooth setting and unpair again, repeat the above only this time on the adaptor hold the button in for 4 seconds until the led flashes again and the app should work.
Always start the app searching for the Bluetooth adaptor before pressing the button on the adaptor as I found this what works the best.