TomTom has a Android app. Though not feature rich, its navigation capabilities are top notch. The voice for TTS is the best I've heard so far, much better then my old Nuvi 750. Routing is great too and it works without data.
I do have to say though, that I've found myself using Waze (another navigation app) much more often. It uses user created/edited maps, so its the most up to date maps you can get anywhere. Not only that, but like Google, it has free traffic, but the traffic is also closer to real-time because it uses the information of other Waze users on the road to gather traffic data. Routing, although sometimes slow to calculate and re-calculate if you go off track, is also good (though some addresses do need to be fixed). Although it's been around for a while, it's still in its infancy. Previously, it only routed between home and work, but has recently added on the ability to route to other locations. With the traffic data it gathers and accurate maps, it's estimation of arrival at a location are near spot on. It does use your phone data though it is light on that, so I keep the TomTom app as a backup. But so far though, I haven't had to use TomTom at all ever since I discovered Waze. Give it a try, even if it in a 4-wheel just going back and fourth to work. The more people who use it, the better it can get.