I love that it's very customizable, so you can make your own rules for each employee/client! The reporting features are easy enough but not overly complicated or overwhelming (it has some helpful tutorials as well).
It would be nice if there was more customization of reports; maybe even add in another way besides just selecting from predefined options? But overall this app does what we need at our organization - keep track of time spent with clients & employees, invoices paid / outstanding etc., easily accessible data via mobile device when away from office.