After you've installed the DIRECTV™ Tablet App, launch the app and tap the Remote icon in the upper right corner. Then tap Remote. You'll have access to most of the button commands found on your DIRECTV remote control as well as additional commands such as slow motion. You also have the ability to change the remote mode to a mini remote, which gives you access to primary DVR controls.
Please note: To use this feature your tablet must be joined to the same Wi-Fi network that your receiver is connected to.