In order to use the CARMERA imagery viewer application in OSX it must be moved out of the "OSX" folder into the parent download folder. Users also may need to update their "Security & Privacy" settings to "Allow apps downloaded from:" the "App store and identified developers."
After moving the CARMERA-viewer app into the main folder you downloaded simply open the application and use the arrows (or arrow keys on your keyboard) to move up and down the block, use the +/- buttons (or Z/X on your keyboard) to zoom in or out. You can use your mouse or trackpad to drag around your view in the imagery. To switch between different blocks use the drop down menu located at the top of the viewer window.
Why must the application be moved?
OSX requires a user to show intent when using an application to access files on their computer (such as the panoramic images located in the "images" folder). The way they enforce this is to require the user to change the folder for the application, for example when you install many applications in OSX you have to drag them into the Applications folder.