As long as we're dreaming up apps that don't exist but should, how about a voice assistant (Ziggy, Maluuba, whatever) that can do macro actions. Right now, none of the voice assistants are easier than just pressing the buttons because I have to keep doing stuff in the voice assistant application. I'd like to get in my car, press one button and say "I'm on my way to work" and have the app turn on bluetooth, turn off wifi, turn off the ringer, then open Inrix or Here Drive+ and have it show traffic/navigation to my office. I'd have a similar macro for driving home. When I get home, I just say "I'm home." and it turns off bluetooth, turns on wifi, turns up the ring volume, etc. I guess I could do all that with NFC tags, but why not voice?
How about a "face-down to silence" app?