First, please check the serial number on the bottom of your PowerDot(s). The serial number is a number sequence after SN letters, starting with last two digits of a year the product has been manufactured, e.g. 15-, 16-...
If your serial number ends with "-02" and your Android OS version is 5.0.1 or higher, then unfortunately, your PowerDot is incompatible with your current phone and you won't be able to use it.
The root cause of this issue lies in a Bluetooth-related fix Google implemented in Android 5.0.2, which have made all of our first batch devices incompatible.
We have addressed this problem in our later batches, however, the only way to make things working for the first batch device users is either to use a phone with older Android version or use your PowerDot(s) with iOS device.
If you end up in this situation, please send an email to email@example.com and we will do our best to help.
Secondly, if your device serial number does not end with '-02', try going through the full Android re-pair procedure and if it still doesn't help, please try restarting your phone.