How do I produce a stream of secure random numbers from AES-Counter mode?

I can do this in less than a day and don't need to take much money for it. I have some questions about the subject though. 1. Do you need it to be pretty? I mean: Do you need a pretty API? 2. You want it to count and on each counter increment to generate a random number between 0 - 700 using AES-CTR ? (this one it's just to confirm that I understood it well..) 3. You want to start the counter on a button click and then to stop when you decide? Printing every result till you asked it to stop or you want to have a display that shows the random generated number each time you press the button?