The "myapp://" is a custom URL scheme used to launch specific applications on a device. This scheme allows developers to create links that, when clicked, open their app directly instead of a web page. For example, if a user clicks a link starting with "myapp://", it will trigger the associated application, provided it is installed on the device. Custom URL schemes like "myapp://" are commonly used in mobile applications, such as those for iOS and Android. They enable seamless navigation between apps and enhance user experience by allowing deep linking to specific content or features within the app.