For Android devices, there is an App doing spaced repetition integrating Evernote: http://www.revunote.com Unfortunately not for iOS. I asked the guys at Revunote whether an iOS version is planned but I had to learn that this is not the case.
Hi there, I´d like to contribute another alternative for using spaced repetition learning with Evernote: I use the App Anki for spaced repetition learning: http://ankisrs.net It´s free and open source. There´s an easy way to link an Anki flash card to an Evernote Note: http://www.screenr.com/FaTH If you on Mac the HMTL string shown in this video for the link can easily applied by using TextExpander. Hope this helps!