At long last, you can get Warner Archive's streaming channel on iPad. Sign up here for a free two-week trial, then go get the app. It's been available on Roku, and having the account allows access on either device. The library is continually growing, and includes loads of things in HD that aren't yet on Blu-ray. The app is Airplay-capable for AppleTV users.
Electric Shadow
THX Tune-up for iOS is free until next week
THX's new app costs $2 starting next week, and is made to turn your iPhone/iPad/iPod touch into a home theater calibration device.
What's the upside to this over the THX calibrator on various DVDs and Blu-rays? You can use the phone/tablet's camera to do color and tint calibration instead of shelling out for blue filter glasses (which aren't cheap or easy to come by).
You can calibrate video via AirPlay and an AppleTV, but to do sound you'll need Apple's iPhone/iPad to HDMI adapter: Lightning connector version, 30-pin version.
Amazon Instant Releases an iPad App (That Kinda Sucks)
On the heels of Hulu Plus releasing an AppleTV app, Amazon has put Amazon Instant Video on the iPad. I downloaded the app, and sure enough...no AirPlay compatibility. Watch everything you want, only on your iPad and not on your TV. I'd love to watch all of The West Wing on my TV, not necessarily so on my iPad.