Complete Invoicing Solution for Free Introduction Crater is an open-source web & mobile app that helps you track expenses, payments & create professional invoices & estimates. #Crater is #free for life with all of the below features catered towards the #freelance and #smallbusiness community. 1. Invoices Create and send professional invoices to clients and save time for what really matters. 2. Estimate Create a quick and detailed quote including prices, discounts, inventory and more. 3. Track Payment Easily keep a detailed note of your transactions and never lose a payment history. 4. Expenses Keep track of your spending on various services with our easy to use expense tracking. 5. Reports Get detailed reports on your invoices with one or various clients. 6. Taxes Input different tax types & calculate them as simple or compound tax per-item or directly on the invoice total. 7. Professional Invoice Templates Choose between three specially designed templates for creating invoices and estimates.