Ramp Receipts - Create a receipts/invoice dashboard for Stripe
Invoice.to - A simple & beautiful invoice generator with Stripe & Paypal
Envoice - Send invoices and get paid on Paypal, Payoneer, Stripe and Square.
Free-Invoice.co.za - Free Invoice Software | Free online tool that helps small businesses to generate free invoices and manage their contact list. It can be used as an alternative to expensive invoicing software and online invoicing applications
InvoiceNeko - An open-source and free invoicing system
Invoice Template - Create beautiful looking invoices in seconds