Our free revenue calculator lets you project how much your business will be making three, five or ten years from now and allows you to play with different churn measures and projection timescales to test for different scenarios.

I found gumroad is the best and easy way to collect people to support the "Buy Me Coffee" way. I build a template with gumroad and It's open-source on GitHub and you can host this on https://vercel.com/ for with your custom domain.