And another one...
Able to locate a remote object of your choice (e.g. a separate laser, led, small picture of jean luc picard).
From your video on kickstarter, there is a picture hanging application. But you need at least two people of this, since the measurement would be displayed on the screen.
If there was a separate object that can be used a locator, you could place the phone on a tripod (or other support) and move the object around on the wall until you heard a beep, then you knew you were in the right spot.
The other alternative would be to be able to set up the laser to point at one point, then the next etc. And for the phone to indicate if it loses location. In fact if you provided the difference between the laser location and the desired spots, I could probably knock up a motorised tripod to move between the points pretty easily.