Personally I've settled on CoPilot Live Premium USA, and this is after trying a bunch of different apps. Huge advantage for me is that it downloads all maps to your device, so you're not dependent on WiFi or cell/hotspot connections. You have a choice of downloading "local maps" i.e. 2-4 states, or downloading the entire US and Canada, and you can switch maps out as you choose. There are regular updates to both the maps and the app. Yep, you've got to pay for it, but you can use it (as I do) on my 700, my Nexus 7, and my GNex. Navigation has been quite accurate (better than my Garmin dedicated unit) and there are a ton of options not present in standalone GPS units. Full download of entire US and Canada is around 2Gb, individual "areas" seem to be around 200-400 Mb.