Loafer is A complete project time tracking and billing application. Allows you to have multiple project files so that you can separate projects by client. You can add multiple projects to a single project file so as to keep all projects for a client, for instance, together. Each project can have it's own currency and billing rate. Each project can have multiple tasks under it and each task can have a different currency or rate assigned to it. A system tray-based dashboard lets you start/stop project times quickly and always gives you an overview of the total time spent on the current project as well as the amount you can charge the client for it.