Harvest is an effective time management tool which allows the home worker to bill clients, monitor expenses, and track time. It provides the option to establish graphical reports to review business data for specific clients, projects, and tasks. For instance, a small business consultant with 5 clients can highlight how much time is required for non-billing activities such as filing and marketing and billable activities such as telephone and e-mail coaching.
Harvest requires no installation, provides a monthly subscription service that the home worker can cancel, downgrade, or upgrade, and allows multiple plans such as a solo plan starting at $12.00 per month. This solo package gives 1 active user account, 20 active projects, and 30 active clients with unlimited invoices. A major plus is a 30 day trial period before a decision is required.
Sources: http://getharvest.com/