^ the idea is good, but not as easy at is seems at first sight. Stars/planets are easy as you're moving in 2D (=no closer/further targets on the same direction). With 'real life' situations, you have to discover WHAT you're aiming the phone at, and that's not easy, even if you have compass and camera input, due to sensor/pointing errors and multiple targets being in the given direction, objects obscuring each other, etc. To reiterate, the idea is cool, and sooner or later somebody will do it, but this Star Droid is far-far-far from that as it does not rely on any actual input from outside sources (apart from Earth's gravity and magnetic field, that is Now, if any of these devices would have a built-in laser distance meter, that would be a very different story.