Waze - Very useful in the GTA or other places where the network is available. Not really a Nav tool IMNSHO
I prefer to always have offline maps, and I found googles beta 'offline' rollout disappointing to say the least, so on my droid I switched to OSMAnd and couldn't be happier, until I switched to the iPhone (long story involving a concrete floor and an loaner from a nephew) and found that OSMAnd doesn't route on an iPhone but provides great detail while sitting in a tent planning out the next section.
I have to say that I prefer a dedicated gps for that function, even a crappy old one like the Garmin 60cx I run.