Past Recorder by Israel’s Ajeera Apps constantly records in the background, saving the last 10 mins of whatever it has picked up. If, within 10 mins, you realize you wish you had recorded something, you can enter the app and save any portion of that conversation or music. Even capture your child’s first words.
http://www.jpost.com/Business-and-Innovation/Tech/Israeli-app-lets-you-record-your-past-494401