Local notifications have minimal impact on your app's frame rate and memory usage because they are managed by the system, not your app's UI thread. They do not run continuously in the background, so battery drain is low. However, scheduling many notifications at once can increase CPU usage briefly.
Schedule notifications sparingly and only when necessary. Avoid scheduling hundreds of notifications at once. Use the system's notification APIs efficiently by updating or removing outdated notifications instead of adding new ones. This keeps the notification center clean and reduces system overhead.
Local notifications require minimal code and resources, so they add almost no size to your app bundle. They do not affect app startup time because notifications are handled by iOS in the background, independent of your app's launch process.
On iOS, local notifications use UNUserNotificationCenter and require user permission. Notifications can include sounds, badges, and custom actions. Android uses NotificationManager with channels for categorizing notifications. Android allows more customization but requires managing notification channels for Android 8.0 and above.
If your app delays loading due to local notifications, you might be scheduling or handling notifications on the main thread during startup. Move notification scheduling to background threads or defer it until after the UI loads to keep the app responsive.