Bill4Time - Your Complete Time and Billing Solution. Simplify your billing. Recover lost revenue.
FreshBooks - The ideal accounting software for small business owners.
Clio - Clio provides a full suite of web-based practice management tools targeted specifically at the administrative needs of sole practitioners and small firms.
Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.
Amicus Attorney - Amicus Attorney legal practice management software empowers lawyers in small firms to do more and bill more by helping to organize the practice, work more efficiently, provide better client service, improve teamwork and capture more billable time.
Active Collab - Active Collab — Task management, Team collaboration, Time tracking & Invoicing app