You can't. Muse is a website designer no application creator.
Because an app is no website. If something is like something else, it so not the same as something else.
Although its looks like an app still it is a website.
You cannot get all the functionalities in a Muse site which you may be looking for into an app.
You can use Dreamweaver for your purpose. See Building and packaging mobile apps in Dreamweaver CC for more info on using Dreamweaver with Phonegap to create mobile apps.