I was unable to use it. It told me location access needed to be enabled even though it already was. Nexus 4 running KitKat.
If you're getting an error saying that Location must be enabled in order to use it, it means that your device claims the GPS Provider, the Network Provider, AND the Passive Provider are ALL disabled when attempting to grab your location.
If you're sure they're enabled in your settings (where the App's error message should take you), I would try restarting the device.
If the issue still persists, please shoot me an email at matt@jackpocket.com and I will help you get it working