Hi @markharrell109 
The preview link is what your app would look like in a browser. In Bubble, there are tools to make the app responsive so that it will look great at any screen size. In regards to a mobile app that you would download from the app store – that is a little bit more complicated because that part of Bubble is in beta phase. To create a mobile app, all of your app’s content must be on one page, and in different groups (that are shown or hidden depending on what the user clicks on). If you create a ‘native app’ page in your Bubble app, you would check this box in the property editor:
And once you do that this popup will appear:
@natedogg has Android and IOS app development courses that you can enroll in to learn how to do this: