Definitely the digital pads or sticks in a game of touch screens depends of our oil in our hands and how much the screen is cleaned. To solve this other product of Tenone Designs, fling.

Useful for games!

Fling

Really good idea, based in spanier innovation (this spiral in stick)

You can see a version for iPhone, “Lling mini”, bad thing… impossible to see the screen, for that you have other external pad with stick iControlPad.