Reverses the scroll direction on macOS. Useful if like to change this setting when switching between using the trackpad and a mouse. You can set the scroll direction via the command line with the following (choosing either true or false)
defaults write NSGlobalDomain com.apple.swipescrolldirection -bool true/false
However this requires a logout / login to take effect.
Running this script toggles the scroll direction via System Preferences and so the effects are immediate.
To add this script to the dock, open scroll-reverse.scpt in Script Editor and save as Application. Add this new app to the Accessibility list (System Preferences > Security & Privacy > Privacy). Drag the new file to the dock. You can change the app icon by right-clicking to Get Info and then pasting an image onto the default image.