SharePoint Add-In

Hi..

I am developing SharePoint Add-In and I want to integrate one already developed SharePoint Add-In to my developing Add-In. (For Ex. I am developing Add-In A and Add-In Survey is already available on store, I want to use functionalities of Add-In Survey in my Add-In A, to achieve Survey functionalities in my Add-In A), OR is there any better way to create Add-In for survey/polling.

Thanks.