Free Invoice Generator - A free invoice generator for startups
Ramp Receipts - Create a receipts/invoice dashboard for Stripe
flyceipts - A fresh look at digital receipts & other documents.
Envoice - Send invoices and get paid on Paypal, Payoneer, Stripe and Square.
QuickReceipts - A mobile app that automatically tracks, organizes, and stores your digital receipts privately on your device.
InvoiceNeko - An open-source and free invoicing system