Fermat-Test was a little experiment with Objective-C and Xcode. First, I wanted a simple test of the fermat theorem (not a proof :-) Wiley did this in the 90s).

Second, I wanted to see how easy it is to bring the Sieve of Eratosthenes to my Mac. The app uses a NSMutableArray (if you enter a high value you are going to create a lot of objects). Watch out, that your mem does not run low.