Over a year ago I was inspired after reading Derek Sivers post on using Spaced Repetition to improve programming skills so I set out to do likewise.

I couldn't find anything that enabled my criteria, so I built it, http://www.Memorific.com is:

1) the usual flashcard stuff with all sorts of question types

2) mobile web experience so I could use it anywhere but offline

3) an ability to easily collaborate on decks, not the usual import/export, but "build together"

4) code highlighting, github-flavored markdown, etc

It's been in beta for many months and we've got the core of our MVP locked in. Hopefully y'all will find it useful too.

Cheers,

Zack