Free Invoice Generator - A free invoice generator for startups
ChargeOver - ChargeOver automates recurring billing, subscription billing, & payment acceptance. A SaaS that integrates with Xero, Quickbooks, & has an API. Free trial.
Bookipi Invoice App - A minimal, beautiful invoice app for freelancers
MinuteDock - Web-based time tracking software designed to integrate with the Xero accounting package.
Invoice.to - A simple & beautiful invoice generator with Stripe & Paypal
Elorus - A super-easy online invoicing & time tracking software