This is an incredibly useful app. I started using it to track recurring events at work, but the more I use it the more areas I find it useful in my personal life too. I really like being able to add any event that I want, in addition to how I measure it. The widgets are particularly useful, and the interface itself makes this a very easy app to work with. I'm very happy with this one and highly recommend it.
WhenDidI - Event Tracker at Google Play market analyse