Invoice Ninja - Invoice Ninja is a free, open-source solution for invoicing and billing customers.
flyceipts - A fresh look at digital receipts & other documents.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
QuickReceipts - A mobile app that automatically tracks, organizes, and stores your digital receipts privately on your device.
GnuCash - A personal and small-business financial-accounting software, licensed under GNU/GPL and available for Linux, Windows, Mac OS X, BSD, and Solaris.
Productfy - The most advanced platform for building fintech applications