Financial Toolbelt - Powerful calculators that help you improve your finances
Profit First Calculator - Calculate business accounts using the Profit First method
Bootstrap Money - How much money can you make selling software?
FB ads budget calculator - Easily calculate your Facebook ads profit potential
Evaluator - A simple calculator app for macOS and Windows
Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.