I built a free & privacy-friendly repayment calculator (tilgungspilot.com) – feedback desired!

Hi everyone, since I was looking for a property myself and most online calculators annoyed me (either totally confusing or you have to leave your email address for "advisors"), I have been working on my own tool over the last few months: https://www.tilgungspilot.com What can the tool do? Real-time calculation: You can immediately see how the purchase price, equity, interest and repayment rates affect the monthly rate and the remaining debt. Special repayments & interest