The visual indicator appearing on an application icon on Apple’s mobile operating system serves to communicate the presence of unread notifications or pending actions. For example, a number displayed atop the Mail application icon signifies the quantity of unread emails within the inbox.
This feature provides a succinct and immediate method for users to stay informed about updates and required attention within their applications. Its implementation dates back to early iterations of the operating system, becoming a standard element of the user experience and contributing to efficient management of digital information. The functionality reduces the need for users to actively open each application to check for updates.