I just bought a 1st generation 16GB iPod Touch from a friend. I know that last year Apple released their $20 "upgrade" for these ipods so that they may have some apps that were originally on the iPhone, like Mail and Maps. The iPod that I bought was upgraded and has these applications on it. When I sync it to my computer/library, to add my own media, will these apps disappear with it, forcing me to repurchase them, even though they were already bought for this iPod, or will they remain on the device? Thanks!