There are a few schools of thought when it comes to achieving sustained happiness. Some people would tell you to look forward: make plans, set goals and work towards getting the things you want. Others would take more of a zen approach: just be in the present moment. And while it may not be as intuitive, others like Jonathan Cohen believe better living can be achieved through taking a detailed inventory of your past.

Inspired by Daniel Kahneman's book Thinking, Fast and Slow, the Expereal app gives you an easy platform to rate your feelings throughout the day and append those ratings with specific notes like where you were and who you were with. You can also attach text descriptions and photos. Expereal's most interesting — and perhaps most useful — function allows users to anonymously share their feelings through Facebook. The app then compares your data with that of your friends, potentially showing correlations.

Cohen's really trying to solve peripheral problem with Expereal. It's the idea that when we remember an event, we usually just remember it for how it ended, tending to forget how we experienced the entirety of the event. But is it possible that the Quant Self movement (Nike FuelBand, Velux Quantee) is doing us a disservice here? What if our generalising memories into one emotion is an evolutionary tool? Or is that having access to that much detailed data will help us see patterns in our emotions, leading to happier lives? Cohen asks that you download Expereal for free (currently iPhone only) and try it for 90 days to find out for yourself.