I used to have an iPhone 4, sold it a few months ago. I just got an iPad 2 and want to install some of the many apps I had originally purchased for the iPhone. Most every "previously purchased" paid app I download from iTunes downloads fine, shows up under apps in itunes but does not show up on the iPad. Example: Downloaded Angry Birds (the original one) through iTunes, it shows up under APPS but it's not on the iPad. Downloaded NAVIGON (that one was $50). It seemed to download fine but never appeared on the iPad. They both say "for iPad or iPhone." Do I have to buy these all over again? I thought they could be used on any device. I don't mind the cheap ones but NAVIGON is expensive.