Invoice Ninja - Invoice Ninja is a free, open-source solution for invoicing and billing customers.

ChargeOver - ChargeOver automates recurring billing, subscription billing, & payment acceptance. A SaaS that integrates with Xero, Quickbooks, & has an API. Free trial.

Invoice Genius - Invoice Genius is a FREE invoice maker app for freelancers, contractors, and small businesses that...

fusebill - Fusebill is the leading recurring billing and subscription management software for businesses. Try Fusebill for subscription billing made easy!

invoicely - invoicely is a free online invoicing platform for small businesses

Elorus - A super-easy online invoicing & time tracking software