Android 15 mandates a shift towards edge-to-edge applications, allowing users to experience apps in full-screen format without black bars. This change has surprised many app developers, prompting Google to provide a temporary opt-out option via the windowOptOutEdgeToEdgeEnforcement attribute for those unprepared for the transition. Historically, Android apps could extend content to the screen edges using specific APIs, but many developers hesitated due to potential UI conflicts. Google introduced insets to help manage overlaps between app content and system UI, but edge-to-edge behavior was not enforced, leading to underutilization. Developers have until August 31, 2026, to optimize their apps for edge-to-edge functionality, as the opt-out attribute will eventually be deprecated. The transition is expected to be seamless for users, enhancing the overall app experience.