Cr-App, they should call it that.
When you use the Mac App store, it remembers your purchases, even the iOS app store remembers. But iTunes is amnesic with your purchases, so you could probably end up paying for the same app twice if you forget. I did a quick experiment with a free app which was already on my Touch. In the App store, I clicked the buy button and iTunes merrily started to download the program after getting the right password.
I would think it should work like Mac App store, once logged in to the same account it should hold the info. It even worked perfectly when I shifted from my Macbook to the Air without having to migrate using any wizard. Just log on in the App program with the correct account and ta-da! Previous purchases intact.
It started when I updated and synced my Touch, suddenly it reported that the Air is not authorised to accept the Whatsapp app on the Touch. So I obediently clicked to authorise, since it threaten to delete the app if I didn't. Strange since it has been working for the past year. Then iTunes declared "Hey Silly, your computer is already authorised".
What the f***?
The Genius in iTunes has dementia?
Then I tried to reinstall the App by deleting it and re-syncing it. It refused to stay after syncing.
Finally it dawned on me, the App has somehow been disabled for Touch. I could not see it in the iOS App store when searching. Also I remembered that after the last direct update on the Touch, syncing has been glitchy, there was even a graphical glitch on the Touch passcode page.
So much for iOS 4.3 "bug" fix.
Ironically, had I not deleted the app directly, it would still be running on my Touch, but it made syncing annoyingly difficult. The worse thing is Whatsapp is a paid app and now it is disabled without any warning. Why? Then the crap app of iTunes goes into a convulsion instead of solving the problem.
Great way to crap on paying customer. Got an App for that?