1. The zip file you just downloaded contains an application that starts with the name IOLab. If your Mac didn't do this for you already, extract the application from the zip file. This step is important - you cant run the application if its still inside the zip file. Double clicking on IOLab.app will start the application.
2. After you run the application for the first time and acquire some data, you will see that a folder called IOLab-Workfiles has been created in your Documents folder. This is where the application stores all data, calibrations, lessons, and lab reports. This folder will not be removed or changed when you delete or update the IOLab application.