freshbooks is really well excuted online invoicing, expense and time tracking software. As a hosted solution it has proved itself over time by consistently improving without becoming over burdened with features and extras you don't need. The creators have intelligently decided two things from my observations. The first is that they have build a solid API that allows others to write plugins. This means they only need to provide a good solid foundation and others can create need specific application add-ons. The second thing is they have listened to their users and reacted accordingly which has improved usability no end.