You asked a very imprecise question. You also gave the impression that you wanted someone else to do your work for you. No one is going to do that for you. Eddy, quite rightly, suggested that you think about the problem like a series of bricks which if put together properly will give you a house. You need to think of what parts you might need to make a banner app. If you are too thick to do that, then give up now, take up a different hobby/career, knitting for example, where you can buy ready made patterns. No thought required, at all. Wait a minute, that gives me an idea, have you learned how to Google yet? Yes, then bloody well use it! 'Banner application c#' should do the trick.
Henry Minute Do not read medical books! You could die of a misprint. - Mark Twain Girl: (staring) "Why do you need an icy cucumber?" “I want to report a fraud. The government is lying to us all.”