Simple Invoices - Never Wait For Clients To Pay You Again!
Invoice SA - Send invoices faster. Get paid faster.
Slimvoice - Insanely simple invoicing
Zoho Invoice - 100% free online invoicing software for small businesses.
Inveezy.com - Inveezy is a free invoicing website with no login.
Invoice Ninja - Invoice Ninja is a free, open-source solution for invoicing and billing customers.