The previous reviews were so old, I had to try it. The download works.
This is for Xboxes that have a "mod chip". (If you don't know what that is, you don't have one. It is a piece of hardware soldered into the Xbox to let you take control.)
When you launch the first time it loads a help page in Safari. The interface is slightly off from Apple standard: In the main window "Xbox Browser", click the button at the bottom, "Open/Close Panel". This reveals a slide out panel with the controls. (That is not logical, since you can't do much with it closed.) Then click the Preferences tab. (That should be in the menu.) Enter the IP of your Xbox, the games directory, and name and password, and where you want the .iso files to be created. The default is your user folder. Change it to the desktop. Then in the left side click Refresh and you should see your games stored on your drive. Select one or more, and click Download Now! (on the right side under the Commands tab). If you get an error, switch the Preferences to Basic Commands.