How to access Workflow5 local storage (set by SetApplicationData) from custom module

Hello, I'm trying to create a custom module in HTML5 viewer SDK. However, the viewer API doesn't have anything to access the Workflow5 application, nor the Workflow5 set the application data to window.localStorage. So, I'm wondering from the custom module, how to access the application local storage used by Workflow5 SetApplicationData activity. or how I can pass data from workflow5 to custom module/view? Thank you.