To cite CityShadeMapper use:

  Francisco Rodríguez-Sánchez & Jesús Sánchez-Dávila. CityShadeMapper:
  Generate High Resolution Shade Maps and Shaded Routes from Remote
  Sensing Data. https://pakillo.github.io/CityShadeMapper

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {CityShadeMapper: Generate High Resolution Shade Maps and Shaded Routes from Remote Sensing Data},
    author = {Francisco Rodríguez-Sánchez and Jesús Sánchez-Dávila},
    year = {2022},
    url = {https://pakillo.github.io/CityShadeMapper},
  }