Scout Sales & Expense Tracker
Automatically import and list your inventory on multiple sites at the same time. Keep track of expenses of all your reselling operations in one place. Scout also includes many other features such as tracking your shipments, keeping track of all your subscriptions to various groups and other recurring services, keeping tabs on your bots and when they renew. There are tons more features for Scout as well. This is a must-have if you're serious about reselling.