On The Job by Stunt Software is an excellent way to track your time and expenses, as well as bill your clients by quickly creating professional invoices.
The interface is straightforward and easy to learn. There’s no need for help files. The dialogues and buttons are all clearly labelled. Even though the interface isn’t customizable, you can change things like date formats, deletion confirmation and timer animation.
Invoicing is simple, and you can restrict it to a single job, client and date range. The built-in templates are well crafted, and the editor enables you to create your own. Outstanding invoices are trackable via the sidebar and overdue ones are flagged.