Mobile app success constitutes a multitude of factors. Some are feats of ingenious programming. Some just hit the right mix of branding and fun. What all successful apps have in common is there’s a developer or many developers that are incredibly jealous. They wish they had thought of the idea and, more importantly, executed it themselves. At the Android Developers Conference, or AnDevCon, in Burlingame, California, I asked attendees what application they wished they had developed.