It's a single link to use to route users to your app(s), for social bios or any post where you want to link users to a specific app or showcase all of your apps. Just sign up, claim a slug and or username, and you'll see the functionality. Only takes a minute!
You can sign up on https://launch.app and once signed in you'll have access to a dashboard to create your Launch page, choose your URL slug and design your page