The ability for me as an employee of my own business (or client) to manage all aspects from invoicing through billing. I can even use it when not at home or away! It's also very easy to add new clients/employees using our dropdown menus which makes adding people quickly super simple!! Nothing really - just make sure you know how everything works before trying anything out because there could be better options available if what they have isn't working well enough for your needs. We were able to track time spent between employees so we knew exactly where any issues might lie within projects being worked upon by multiple team members.