Once you have launched GROWLr the first time, a dialogue box will appear prompting you to allow or disable location sharing while using this app. Your GPS coordinates are necessary to deliver the most accurate results for other GROWLr users close to your area. The alert will read:

"GROWLr" Would Like to Use Your Current Location

Click "OK" to allow the app to use your location when the app is in use.  GROWLr requires access to your GPS to function.