I've started using Waze and really like it. Especially for the police sightings.
+1 on Waze. The only problem is that it does run in the background. But if you are in your car, then you more than likely have a car charger so that shouldn't be an issue. When you "stop" the program, it stops everything....background data.
I do like the "police" feature. It also will tell you where there are stoplight camera's, accidents, detours, traffic. You gather points also that you can redeem for discount gas (I don't know how you redeem them, just says you can).
The voice also for WAZE is better than Google. For example:
Google: "In 1000 ft, take exit 123a"
Waze: In 1000 ft, Elm street exit will coming up"
You can choose between a female voice or a male voice.
I use both Inrix and "Beat the Traffic". Both are standalone and do not run in the background. Usually they agree but sometimes one app will show a problem ad the other won't for the same location. I usually open them both before I leave for work just to see what's what on my commute. Not just for traffic but also for construction lane closures and stuff like that.