If you happen to be an Evernote user, you might find 'Reflect' to be an interesting companion app. As its name suggests, it's a web app that allows you to reflect on any of your Evernote notebooks (or even all of them). You can further break this down by any tags assigned to your notes. It then sets a review schedule for you based on how many times you want each note to show up and the total notes (flashcards) you want to see in each review session. You can then choose to receive email reminders at a set time of day.

The way I currently use it is to review all of my e-book highlights, sticking to one book a day. It's a great way to be reminded of all the books and interesting points that I read through months or years ago. I consider this to be one of the huge advantages of e-books and could never imagine going back to using paper books again. In fact, my remaining paper books nowadays function mostly as monitor risers (admittedly it looks far less elegant than one of those over-priced £20 risers on Amazon or eBay, but it does the job!).

All in all, Reflect comes in handy for any type of learning. Just think of it as a digital and far more sophisticated version of those little exam-time revision notes you used to scribble down or print on pocket-sized cards.