It requires GPS. Crashes on my tablet.

Also, see their Facebook. They publicly post GPS location of winners, together with StreetView. Is that stated in the app? It can be a privacy concern.

  com.carrotpop.www.smth         E/AndroidRuntime: FATAL EXCEPTION: main
        java.lang.IllegalArgumentException: requested provider gps doesn't exisit
        at android.os.Parcel.readException(Parcel.java:1429)
        at android.os.Parcel.readException(Parcel.java:1379)
        at android.location.ILocationManager$Stub$Proxy.requestLocationUpdates(ILocationManager.java:646)
        at android.location.LocationManager._requestLocationUpdates(LocationManager.java:660)
        at android.location.LocationManager.requestLocationUpdates(LocationManager.java:482)
        at com.ansca.corona.CoronaSensorManager$1.run(CoronaSensorManager.java:163)
        at android.os.Handler.handleCallback(Handler.java:615)
        at android.os.Handler.dispatchMessage(Handler.java:92)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:4745)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
        at dalvik.system.NativeStart.main(Native Method)