SHREDDER for iPhone
Shredder Chess was made accessible for VoiceOver users two years ago, along with another chess app named Chess-wise from a different developer. You can read the AppleVis review of the free, lite version of Shredder Chess at:
P.S. This was all done with feedback from members of the viphone list who contacted the developers, so it has been checked out. It's just that many of the apps that were made accessible during the period when AppleVis was getting started never got detailed write ups of their background.