Free tools for indie app makers
Small calculators from Plask (plask.dev), for the money questions that come up when you sell apps. They run in your browser and need no account.
App Store and Google Play proceeds calculator
Price, tax, commission, proceeds: what Apple or Google keeps from a sale, step by step.
Indie developer tax set-aside calculator
How much of your profit to put aside for tax, per month and as a 12-month reserve.
Run the numbers on your real sales
Plask shows proceeds, costs and profit for every app and site you run, from the sources you connect. One product is free.