Numeral presentation on an IPad with correct response scoreable.

I'd like to have single digit numbers automatically presented on an IPad or IPhone and the observer responding either by voice or by manual input such as by using a large number pad. The responses need to be scoreable as correct or incorrect. The size of the numbers, the presentation time, the frequency of presentation, the number of presentations, the randomness and the total number of presentations are parameters I'd like to be able to have control over. It would also be great if the presentation of each new number could be triggered mechanically. The application is to score how accurately a person can identify random numbers. Thank you in advance and looking forward to your reply.