I purchased Numbers on my desktop for $19.99, but need it on my ipad and iPhone. Must I repurchase it on each device? This is the only app I have this problem with.
iWork applications on the Mac are totally different than the ones on iOS devices. I'm afraid you will have to buy them again for iOS if you want them on your iPhone and iPad. But the good news is that the iOS version is a universal application, meaning it works on both versions for iPhone and iPad.