Invoice Ninja

Founded in 2014, Invoice Ninja is an open-source invoicing, payment, and expense tracking application designed for freelancers and small to medium-sized businesses. The company's mission is to provide a free and powerful tool to help businesses manage their finances efficiently. It offers both a self-hosted option for developers and a hosted SaaS solution, providing features like quote creation, time-tracking, project management, and integration with over 40 payment gateways.