Yeah, you may find bugs, but they are not easter eggs. You will not find any hidden goodies in most Apps. If an app has a feature, most people would be upset that it was not documented, instead of being happy they found it. That is the realm of games.
Some easter eggs are placed in games just to give players that "I found it" feeling. But also, many are added into games to help the play testers play through the game. Often times play testers may have to play through a game more than twenty times, and that would take too damn long without getting "invisible" or "god mode". These are the ones that cannot usually be stumbled upon, like, for example:
Type in "up,down,up,down,left,A,B,A,A,A,A,up,left+A+B,Y,Y,Down"
No one can possible just figure that out. Then game companies just leave them in to get free media coverage. If secrets keep trikling out, then that is longer that a game will stay in magazines and online.
"I attribute the quarrelsome nature of the Middle Ages young men entirely to the want of the soothing weed."
-Jerome K. Jerome(1859-1927),Writer