I got one of these for my wife when they first came out 2 years ago, item listed as compatible with android 4.3 and above. Unfortunately, the list of supported devices in the android realm had unstated requirements (such as BLE Bluetooth) that meant most android devices at the time would not work; including my wife’s phone, a Galaxy S3. The list of actual supported android devices was tiny (about a dozen devices); and that list did not grow longer in the time since release.
Basically, consider this as only compatible with Apple iOS devices, not android. If you have an iPhone, you can probably use it. Android device? Don’t waste your time.