One minute
WorkWork WP
WorkWork is a small and simple time tracking application for people who just want to track their time at work without inputting complicated data. Simply tap the start text when you start working and the stop text when you leave. If you forget to start or stop it on you can change the time in the time selector.
Given that microsoft no longer supports windows phone you can no longer get the app. Previously it could be downloaded from the Windows Phone Market.
If interested you can download the source code on github.
The source code for WorkWork is available under the BSD license.