A new, fully modern version with new features! Now published and supported by James Lewis. Will run on your Mac if it has an Apple Silicon processor.
The most obvious new feature is the display of the power needed to overcome the three forces you experience as a rider: aerodynamic, gravity and rolling resistance.
There is also a new section for simultaneously exploring up to six segments of a ride. That means you can model an out-and-back course including a flat section, a slow rise, and steep hill. It's very interesting to try out different strategies for using your power.
App Store link.