It is a service for tracking how you feel/think your work week went. We ask you 5 questions when you sign up, and then prompt you to complete this questionnaire every week. Over time, as you record more data points (about weeks of work) it provides insight into how your work life makes you feel/think and how that has changed over time.

It is heavily inspired by the process of agile retrospectives [1].

Hope that helps clarify.

[1] http://searchsoftwarequality.techtarget.com/definition/Agile...