Great idea for storing happy memories to call on when things may seem a bit challenging. I liked the idea of creating my own buttons from photos, although I couldn't get it to work but it was probably just a teething issue on the early release.
You may not have heard of the HappiJar app, but they currently have over 5,000 users and seen over 65,000 moments of happiness saved away using it.
You save special moments onto a sewing buttons which are then dropped into your own personal Happiness Jar. Then when you are in need of a reminder of how lucky you are, you simply shake it and one of your happiest moments are pushed back out to enjoy.