Now your app is ready. All visuals and texts have been added, all tests are done. Congrats !
You only need the ultimate step to bring this experience to your users: setting the application public. To do so, go to Facebook Developer onto your app details. You might already used this interface to create your app.
Go to the tab Status and Review, click on the activation button to set the app online.
Notice: Facebook Developers might require you to define an email in the section Settings before you can set the app online. This is mandatory to get alerts on your app, when needed.