You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature currently requires accessing the site using the built-in Safari browser.
I am now in my estimated invitation/configuration/delivery window. When I sign into my account, will the invitation show up on the My Tesla page or do I need to hit the "manage" button?
If you click the Manage button and then see the option to start configuring then that means you were invited to do so. If you just see your typical reservation information it means you haven't been invited to configure yet.