Installing UDM on a Mac:

Download the .pkg file from:
  https://unihedron.com/projects/darksky/cd/Mac/

Open/Click on the downloaded .pkg file in your Downloads folder.

Open/click the .pkg file to start the installation.

An error will pop up saying that the .pkg file No Opened because Apple could not verify.

Click on the Apple Icon (top left of MacOS.

Click on System Preferences.

Click on Privacy & Security.

Scroll down to where the file is listed, and click on the Open Anyway button.

Click again on the new Open Anyway button.

You may have to enter your administrator's password.

Follow the prompts to continue.