Often I download apps when they are free and then never get around to using them. Then later on I might want to use the app and it will have left free status and the author is charging for it. The issue is that I usually can't remember if I got it when it was free and thus would be a free download again for me or if I will be charged. Once you select buy in the app store if you already own it you re download it at no charge even if it currently is not free, but if you don't already own it you will just be charged the current price and it will download. Is there a way to know quickly if I already own it? Or a way to print a master list of apps you own?