Based on the Feeling Wheel developed by Dr. Gloria Willcox, this app allows you to track your emotional state over time. Feelings are tracked on a per user basis and can be reviewed to discover trends.
Give the app a try here (it's mobile friendly). It's built using the Meteor framework.
Sometimes during peak usage times, Meteor's hosting can be a little unresponive. If Meteor reports that the site is unavailable, try refreshing the page.
Please see the issue tracker for planned features/known issues.