Un angry man that he has dropped his iPhone from his hand too many times, he thought that it would be good if he made a foil that would help to better fix the terminal when it is held in his hand. After a little too much thought, he made a foil from emery which he stuck on the back of the terminal and you can see the result in the images in this article. The man's idea came a little late because an accessories company produces for some time such a foil.
I don't know how convenient it is to hold something like this in your hand, but for the clumsy it could be useful. For the rest, I think it's a much too quiet idea.
