iPhone: how to see if GPS is working

Is there a way where I can see if GPS is working? Or what the location service is using right now and why it is not using GPS?

(Because the location service has become very inaccurate after a recent jailbreak I did and I was wondering how I can check if it is really not working anymore or if I just had bad luck.)


I'm guessing turning off WiFi, standing outside and opening up Maps.app would do the trick, if it correctly displays where you are it works, if it doesn't... it doesn't.