TypingDNA Authenticator - 2FA codes in your browser, secured by the way you type
Invoice Ninja - Invoice Ninja is a free, open-source solution for invoicing and billing customers.
Cotter - One-click phone number login and checkout
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
Auth0 - Auth0 is a program for people to get authentication and authorization services for their own business use.
GnuCash - A personal and small-business financial-accounting software, licensed under GNU/GPL and available for Linux, Windows, Mac OS X, BSD, and Solaris.