Never tried to become a Grandmaster by using a chess program on an iPhone, though.
“The basic problem is that it’s incredibly easy to cheat with a phone,” says Nigel Short, an English chess grandmaster who once was ranked third in the world and is now 60th. “You can have some application running on your phone, and it’s quite easy to conceal. … My dog could win a major tournament using one of these devices. Or my grandmother. Anybody could do this.”