I love Pluralsight and they have a pretty nice iPad app, but fairly often I'll be in the middle of going from one segment to the next and it will fail to retrieve the video leaving me with a black screen. I can exit the app, restart the app etc. but I can't watch anymore videos. My solution in the past has been to hold down the button that completely powers off the iPad and then do a cold boot. This causes everything to start over. If you have an app that hangs, there's now an easier way to teach it a lesson. Plus this is useful if you just feel like killing an app you don't want your spouse to know you were using. (You know like the one you use to buy anniversary gifts, yeah that's the one).
The key is the multitasking menu. You can get to it by double-clicking the home button ( or by awkwardly swiping four fingers up if you have the multi-touch gestures enabled under settings). This brings up the running apps on the menu bar at the bottom. Now you can touch and hold an application. A little red circle with a minus symbol appears as shown in the image. Touch that icon and the app dies without so much as a whimper. Then you can just launch it again and if you're lucky the hung behavior will be cured.