
Description: OpenSourceBilling is an open source billing and invoicing software designed for small to medium sized businesses. It allows creating and sending professional invoices, tracking payments, managing clients, products and invoices. It can integrate with payment gateways.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: Crater is a free and open source browser-based invoice app for small teams and freelancers. It allows users to create professional invoices, estimates, expenses and track them online with no limits.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API