well since vblue evidently believes readers here are psychic and can find any random thread he mentions, let me give specific answers to the questions asked.
Waze does indeed offer full touch, and is AppRadio-compatible thus uses the external display in driving-mode. however im disappointed that since being acquired by google, waze is now delivering popup ads onto your screen while youre navigating -- wtf. this should last until somebody crashes and sues google for making them deal with an ad for Taco Bell while driving.
the other GPS apps are all disappointing -- MotionX doesnt offer external display support unless you pay for it. Garmin doesnt offer it. Google Maps doesnt offer it. Apple Maps doesnt offer it. with a parking break bypass you can mirror all of them to the screen, but can not touch any of them. in my tests even if mirrored Siri does not play directions thru the HU, only the iphone speaker (WEAK!!). also, if you have a dock station for your phone on the dash you need one that goes into landscape mode in order to mirror to the fullscreen -- and then it's going to look pretty silly because you have your phone and HU showing the same exact thing right next to each other.
contrast this to what is one the Pioneer website:
You also have the option of using the built-in Google® Maps on Android devices and Apple Maps on the iOS platform. With all of these choices including voice guidance and on-screen control of maps, AppRadio really knows navigation and gives you more ways to get to where you are going
http://www.pioneerelectronics.com/PUSA/Car/AppRadio/AppRadio+3+(SPH-DA210)
...in my tests so far, this isnt true for Apple Maps. so, so disappointingly.