I use my iPads in the gym a lot. My favorite use is teaching the bones and muscles. My favorite apps are Speed Bones Lite and Speed Anatomy Lite. These are both free. Of course, it is a game where they rack up points, but they get lots of practice naming the bones or muscles. I have them play in pairs so many get a chance to do it, and they can help each other. I have had the highest grades these past 2 years on their identification test than I have ever had.
Other parts of the anatomy are great shown on the iPad (Discovery Learning, Nova). They love seeing the heart beat, and pump blood!
Grading is quick with the iPad. I connect directly to our district's grading system and put the grades in directly.
There is a iPad glove that you can put on the iPad. It has a hub on the back with elastic ( I'd like Velcro) that straps to your hand so you don't drop your iPad.
Fun times with all the new inovations, even for a digital immigrant like me!