Free, cross-platform and offline-first invoicing solution that syncs.
Avaza - Beautiful Projects, Timesheets, Expenses, Quotes & Invoices for Small Businesses
Slimvoice - Insanely simple invoicing
Zoho Invoice - 100% free online invoicing software for small businesses.
Envoice - Send invoices and get paid on Paypal, Payoneer, Stripe and Square.
Bill.com - Bill.com provides ACH payments processing, automates your accounts payable and accounts receivable processes.
Brisk Invoicing - Easy and intuitive online invoicing helps businesses look professional and stay organized.