New to the iTunes app store is this ESP test, which is essentially the Zener card set on the iPhone. While cool, there are two things to consider. The first is that it’s a buck, which is a lot for something so simple – but developer overhead is developer overhead. The second is that computers absolutely suck at randomizing things, so this isn’t much of an actual science tool and more of a novelty. Still, if you like that sort of thing.
I’d recommend our good pals at Vitaflo (old timers will remember these guys), which still has the randomized problem, but is free. Or, you can get a sample (not a full set) of the cards at GBFans.com for a tenner. Or get a full, official set for $12.99 online.