You may want to delete apps for various reasons (e.g. you do not have enough space). You can re-download your paid apps later without re-purchasing. To do this, launch the App Store, tap Purchased on iPad; tap Updates then Purchased on an iPhone or iPod Touch; processed to find the app you want to re-download. If you have a lot of apps, you can sort by app name and/or most recent. You can also view all apps that have been purchased or you can just view purchased apps that are not currently on the iPad. Then tap the download button.