The green Application button always starts a new form.
If you want to open a saved draft of an application or a past application that was already submitted, click the person icon in the bottom menu to go to your personal account page.
Open the My Brands section of the page. You will see all of the draft applications you have started plus any applications that are submitted, more info, approved, or not approved.
Click the Edit button next to the application to open the form.