Field Spotter is a mobile-first progressive web app to display live Amateur Radio POTA, SOTA & WWFF spots on a geographic map, and on a frequency band. Designed for use in the field to locate park-to-park and summit-to-summit opportunities in a more intuitive way than the respective websites' spot lists. It can of course also be used from home by POTA, SOTA & WWFF chasers.
Use it at https://fieldspotter.radio.
Read more about the project at https://ianrenton.com/projects/field-spotter.