To individually download and install app updates, tap Updates. Tap Update All to download and install all available updates at once, or just tap Update next to the individual app you want to update. Note: Apps update automatically over Wi-Fi, unless you turn off the option in Settings > iTunes & App Store.
To delete an app you downloaded from the App Store, touch and hold its icon on the Home screen until it starts to jiggle. Tap to delete. If you delete or drag all apps out of a folder, the folder is automatically deleted too. When finished, press the Home button. Note: Deleting an app also deletes all of its data. You can redownload any app you’ve purchased from the App Store, free of charge. You can’t delete built-in apps.