Self-tracking devices are all the rage these days. I went to the Apple store, and there was practically a whole wall of them. They were all uni-taskers though. There was one for cycling, another for running, and one for golfing. Amiigo, an Indiegogo campaign with four days left to contribute (but funded to completion five times over as of this writing), aims to track multiple exercises and figure out what you're exercise you're doing automatically.
There's a bracelet and a clip for your shoe, and Amiigo does the rest. There will be hundreds of exercises baked in, but you will also be able to create your own exercises, and Amiigo will theoretically figure out on its own that you're doing it again. Progress is viewable via your smartphone.
Here's the pitch:
Sounds pretty awesome if it works as advertised. A $99 contribution will get you one by June.