I can confirm that as Mike above said:
1. Double-clicking the app gives the error, "The application "AShortHike.app" can't be opened." Open a terminal window, go to the folder containing AShortHike.app, type "cd AShortHike.app/Contents/MacOS", then "chmod +x AShortHike".
2. Double-clicking the app gives an error that the app can't be opened because MacOS can't verify the developer. Instead, two-finger click on the app, then select Open from the context menu, then Open from the warning dialog.
WORKS on macOS Catalina 10.5.5 on an iMac 27-inch Late 2013.