Mobile push notifications are essential for maintaining user engagement by delivering timely alerts and updates directly to users' devices, even when apps are not open. These notifications serve various purposes, from informing users and prompting app interactions to providing critical updates, thereby playing a vital role in mobile app ecosystems. The implementation of push notifications requires developers to handle technical components such as notification services, APIs, device registration, payload formats, and app lifecycle management, using platform-specific services like Apple Push Notification Service (APNs) for iOS and Firebase Cloud Messaging (FCM) for Android. Opt-in rates and engagement statistics vary between platforms, with Android generally seeing higher opt-in and open rates due to default settings, while iOS requires explicit user permission. The effectiveness of push notifications can be enhanced through personalization, optimal timing, and the inclusion of rich media, leading to improved retention and conversion rates. Different industries, such as e-commerce, media, and fitness, benefit from tailored notifications that drive engagement and conversion. Developers must also manage token expiration and ensure reliable delivery while adhering to the guidelines of respective platforms for payload structure.