I had CamerAlert on my previous 3GS and it was brilliant then upgraded to 4S and had problems but the folks at CamerAlert support were brilliant and sorted it out for me; it just took some details and 30mins and then up and working perfectly. The app is fantastic but what’s even better is the support that you get when there’s a problem. 5 star Service.
This is about as easy as it gets. Link to your database account and allow auto update. My husband has used these speed camera alerts for a few years on his phone and satnav. So pleased it works on my Motorola Xoom.