Enabling the app is the first step to install DiscountDuck on your store.
To enable DiscountDuck, go to the configuration page of the app and click on Enable, this will install the widgets and all DiscountDuck features on your store.
It can take a few minutes for the widgets to appear of your store ( 3 minutes maximum )
Note : DiscountDuck only add a "quick load script" inside your liquid file and remove it when you disable the app, so the app is 100% safe to install and will never break anything in your theme.