"I haven’t seen any commercial products that put together all these different things" (emphasis mine). There appears to be more to Cerego than simple spaced repetition, but I can't tell exactly what right now because it is in limited beta.

I used "Mental Case" on the iPhone a few years ago, and it had a simple implementation of spaced repetition, but it did not adjust itself to my progress very well. I would like to find something better; if you know of anything specific besides the Wikipedia article, please post it.