Hi Janice
The GoSweetSport <=> Shopify integration app is installed from GoSweetSpot, not Shopify.
In GSS, go to Administration=>Integration menu and select Shopify. This will take you to a config menu and, once you enter your Shopify store address, GSS will be enabled on your store and the App will appear in the Shopify Apps list.
Hope this helps.
Cheers, Paul