Hello Developer,
Thank you for making this informative site.
CurveFitter is a free and easy-to-use curve fitting app, Windows version. Would you consider adding it to the list?
The introduction is given at https://welsim.com/products/#curvefitter
Docs for more details are https://docs.welsim.com/curvefitter/curvefit_overview/
The download link is available at https://welsim.com/download/.