The worst part about mobile gaming is touchscreen controls on games that were meant for physical controls. A big example of this is the array of emulators available for Android, made to play games with controllers in mind using touch controls. There are solutions for this, such as USB and Bluetooth controllers, but this person decided to take a more unique approach.
He modded the shell of an original Game Boy to fit a Galaxy Nexus case, then wired the internals of a Wiimote to the buttons. Now he has a Game Boy that holds his phone in place and has Bluetooth guts. Using the Wii Controller IME app, he can play emulators (and other games) using the Game Boy. It’s a pretty fantastic approach that looks great. However, it only has a few buttons, so the modder is planning to add two more to the back (the Wiimote has two more buttons to wire to). If you want to try this mod out, hit the source link!