If you have just purchased apps from the LeapFrog App Center for your LeapPad Academy or Epic tablet and they are not showing up on the device, power cycling the tablet and re-connecting to your Wi-Fi network will prompt the automatic download of your purchases.
If you have purchased apps from the LeapFrog App Center on LeapFrog.com, please ensure you are using the same Parent Account email address that you initially used to register/set up the LeapPad Academy or Epic tablet.