At Hexagon we use this system internally to track time, improve estimates and do some basic resource accounting.

We are far from happy with it and we have some big plans for it.

It certainly is not yet at a standard of functionality where we would consider it to be a saleable product.

You can use the demo version if you want to, by creating yourself a Username, then a Project, then entering time against that project, then reporting on progress to-date.