In the Preview view, you can preview your application.
Click Mobile mode () to preview the application as it will appear on a smartphone. Click Mobile mode () again to return to the editing view.
As you edit your application, you can move between the Data Sources, Layout, Pages, and Preview views by clicking the appropriate link at the top of the page. When your application is complete, click Save to save it.
Click View as app to run the application. If you have not saved the application, a Save Confirmation dialog displays, asking you to save the project to make your changes effective on the application.