The HDHomeRun Prime is a new CableCARD TV tuner that plugs into your home network router. The HDHomeRun app piggybacks on that, letting you watch, pause, replay, and even record live TV right on your iPad. It's pricey, limited, and a little buggy, but it works.
Just to clarify, the app requires an HDHomeRun Prime, which sells for $249.99. I'm in the process of reviewing it, and so far it's fabulous. The app costs $17.99, which definitely seems steep, but for the moment there's nothing else quite like it.
After running the initial setup of the HDHomeRun Prime on my PC, I installed the app on my first-gen iPad. It immediately detected the tuners, and in seconds I was watching live TV. And I found I could continue watching it even while another live show was playing on my PC. (The Prime provides three tuners, so I still had one to spare.)
The app offers basic DVR functions: pause, 8-second rewind, and 30-second skip. You can record whatever you're currently watching, but you have to stay on that channel; HDHomeRun can't take advantage of more than one tuner (meaning you can't record one show and watch another). Thankfully, you can turn your iPad off or switch to another app and it'll continue recording.
However, that's where the DVR options end. You can't schedule recordings, and the app shows only a basic channel guide--you get no actual program information. That definitely limits some of HDHomeRun's appeal; you're effectively stuck with flipping channels to see what's on.
Specifically, SD channels, as the app doesn't support HD. Likewise, it can stream only those channels that have the embedded "copy freely" flag from the cable provider. I'm on Comcast; most of my channels are so flagged. But AMC isn't, so I can't watch, say, "Mad Men." Your mileage may vary depending on your service. (It would be nice if developer Elgato Systems offered a free lite version so users could test the waters before spending $18.)
SD looks OK on the iPad; it's a far cry from HD, but good enough for casual viewing (and a perfect match for the iPad's 4:3 aspect ratio). The bigger issue is consistency: in my tests, full-screen video suffered from frequent bouts of pixelation and the occasional freeze (especially after rewinding or quick-skipping). Sometimes the video would just disappear entirely, replaced by a "no content" message.
So, is it worth buying an HDHomeRun Prime just to get the HDHomeRun app? Probably not. But if you do decide to buy one--and I think it has the makings of a killer product--the app is pretty nice to have. Basically, it turns your iPad into another TV, one you can carry from room to room.