Thanks for posting in the forums! That's a great question! The iPad and AppleTV will work for what you are looking to do.
However, if you are looking for a device that you can connect to your TV and just open up the application, without using a mobile device, I would recommend a connected device. Any connected device will work with the Slingbox SOLO, PRO-HD, 350 and 500.
Below is a link to a page on our web site that explains what a connected device is and what ones you can use:
Hope this helps!
The Sling Moderation Team