Orbis Timesheets is a simple timesheet application within WordPress and can be used in combination with Orbis. Easily register your time on projects or subscriptions and connect your registration to a specific category. All time registrations has to be filled in with a short work description so you always can see what kind of work you did for a client or a individual project.
The plugin adds some nice graphs and stats to give you as much information as needed. Of course you can see how much time was spent on a project.