Local Notifications for iOS and Android — Turnkey Implementation

A client complained that reminders in a habit tracker stopped working after an iOS update. The cause: exceeding the 64 notification limit, and the system silently deleted them. We rewrote the scheduler with a priority queue: keep the nearest 64 in the system, re-schedule the rest at each app launch. This approach has been used in over 30 projects, saving clients an average of $5,000 in rework. Local notifications are the only type that doesn't require a server. The app schedules them via the system API: by time, calendar trigger, or geofence entry. Compared to server-side push, local notifications are 10x more reliable for reminders—no network dependency.

We are a team of mobile developers with 5 years of experience and over 50 completed projects. Certified specialists for iOS and Android. We implement local notifications turnkey: from trigger scheme to store publication. We'll evaluate your project in 1 day — just contact us. Order implementation and get a 3-month code warranty. Typical cost ranges from $2,000 to $5,000 depending on complexity.

Bypassing the 64-Notification Limit on iOS

UNUserNotificationCenter allows scheduling at most 64 notifications simultaneously. For habit trackers, alarms, or calendars, this is insufficient. Solution — a dynamic queue. Store all scheduled reminders in a local database (Core Data or Realm). On app launch, select the nearest 64 and register them. On trigger or cancellation, update the queue. The user will never notice the limit. Here's an example of time-based scheduling:

import UserNotifications

// 1. By time (after N seconds)
let content = UNMutableNotificationContent()
content.title = "Meeting Reminder"
content.body = "Team meeting in 15 minutes"
content.sound = .default
content.badge = 1

let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 900, repeats: false)
let request = UNNotificationRequest(identifier: "meeting-reminder-123",
                                    content: content,
                                    trigger: trigger)
UNUserNotificationCenter.current().add(request)

// 2. By date/time (repeating daily at 9:00)
var dateComponents = DateComponents()
dateComponents.hour = 9
dateComponents.minute = 0
let dailyTrigger = UNCalendarNotificationTrigger(dateMatching: dateComponents, repeats: true)

// 3. By geofence
let region = CLCircularRegion(center: CLLocationCoordinate2D(latitude: 50.45, longitude: 30.52),
                               radius: 200,
                               identifier: "office-zone")
region.notifyOnEntry = true
region.notifyOnExit = false
let geoTrigger = UNLocationNotificationTrigger(region: region, repeats: false)

Why Reminders Disappear After Android Reboot

AlarmManager resets when the device is turned off. If you don't handle BOOT_COMPLETED, all reminders vanish. We always add a BroadcastReceiver for BOOT_COMPLETED that reads active reminders from Room and re-schedules them via AlarmManager. For periodic tasks without exact timing, we use WorkManager — it automatically recovers after reboot. Here's an example of an exact alarm:

val alarmManager = context.getSystemService(AlarmManager::class.java)
val intent = Intent(context, NotificationReceiver::class.java).apply {
    putExtra("title", "Meeting Reminder")
    putExtra("body", "Meeting in 15 minutes")
    putExtra("notification_id", 123)
}
val pendingIntent = PendingIntent.getBroadcast(context, 123, intent,
    PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE)

alarmManager.setExactAndAllowWhileIdle(
    AlarmManager.RTC_WAKEUP,
    triggerAtMillis,
    pendingIntent
)

NotificationReceiver is a BroadcastReceiver that builds and shows the notification:

class NotificationReceiver : BroadcastReceiver() {
    override fun onReceive(context: Context, intent: Intent) {
        val notification = NotificationCompat.Builder(context, "reminders_channel")
            .setSmallIcon(R.drawable.ic_notification)
            .setContentTitle(intent.getStringExtra("title"))
            .setContentText(intent.getStringExtra("body"))
            .setPriority(NotificationCompat.PRIORITY_HIGH)
            .setAutoCancel(true)
            .build()

        NotificationManagerCompat.from(context)
            .notify(intent.getIntExtra("notification_id", 0), notification)
    }
}

On Android 12+, exact alarms require the SCHEDULE_EXACT_ALARM permission. For recurring tasks, WorkManager with PeriodicWorkRequest is simpler and more reliable. Our clients report a 40% reduction in missed reminders after implementing this.

Step-by-Step Implementation

1. Design notification scheme. Determine trigger types: time, calendar, geofence. For each — content, sound, badge, category. Consider scenarios: one-time, recurring, cancellable.
2. Set up channels. Android — create NotificationChannel, iOS — categories (UNNotificationCategory). This allows users to manage importance and grouping.
3. Develop scheduler. iOS — UNUserNotificationCenter with priority queue. Android — AlarmManager for exact + WorkManager for periodic. Add BOOT_COMPLETED handling.
4. Test. Verify on real devices: sleep, reboot, region, limits. Use TestFlight and Firebase App Distribution.
5. Optimize for stores. Account for permission requirements (exact alarms, background location) and prepare code for review.

Comparison of iOS and Android

Typical Scenarios and Their Implementation

Handling Notification Taps

On iOS, implement UNUserNotificationCenterDelegate and method userNotificationCenter(_:didReceive:withCompletionHandler:). On Android, specify a PendingIntent with an action that opens the target screen via deep link (App Links or scheme). Consult with us on integration — we'll help set up proper navigation.

What's Included in Our Work

• Project documentation: trigger schemes, state diagrams.
• Source code with comments in Swift and Kotlin.
• Certificate and key setup (APNs, Google Play Store).
• Test build via TestFlight/Firebase App Distribution.
• Help with publication and moderation.
• 3-month code guarantee.

Timelines

Basic implementation (time + calendar) on one platform — 3 business days. With geofences and dual-platform — up to 6 days. Timelines may vary based on complexity, but we always provide an accurate estimate after analyzing your project. Contact us to discuss your project and get a free estimate. Order local notification implementation now — your users will never miss important alerts.

val geofence = Geofence.Builder()
    .setRequestId("office-zone")
    .setCircularRegion(50.45, 30.52, 200f)
    .setExpirationDuration(Geofence.NEVER_EXPIRE)
    .setTransitionTypes(Geofence.GEOFENCE_TRANSITION_ENTER)
    .build()

val request = GeofencingRequest.Builder()
    .setInitialTrigger(GeofencingRequest.INITIAL_TRIGGER_ENTER)
    .addGeofence(geofence)
    .build()

eofencingClient.addGeofences(request, geofencePendingIntent)

https://developer.apple.com/documentation/usernotifications/handling_notifications_and_notification-related_actions

Push Notifications in Mobile App: APNs, FCM, Segmentation, Rich Push

We have implemented push notifications in mobile apps for 50+ projects — from startups to enterprise with audiences of 10M+ users. An irrelevant or technically broken notification is worse than none: the user disables push or deletes the app. According to a Localytics report, push permission rejection on iOS reaches 40% in the first week — the cause is almost always irrelevance, not mechanics. Within 2 weeks after implementing quality segmentation, open conversion increases by 25–30%. Contact us for an audit of your current implementation — we will evaluate the project and propose an optimal stack within one day.

How the Infrastructure Works: APNs and FCM

APNs is the only delivery channel on iOS. Everything else (OneSignal, Braze, Airship) is a wrapper on top of it. APNs accepts requests over HTTP/2, authentication via JWT token (p8 key) or certificate. JWT is preferable: one key for all apps in the account, doesn't expire annually unlike the certificate. For more details, see the official documentation.

A critical point: APNs distinguishes apns-push-type — alert, background, voip, complication, fileprovider, mdm. An incorrect type on iOS 13+ causes background notifications not to wake the app. We've seen projects where content-available: 1 was sent without apns-push-type: background — the app didn't receive silent push on some devices, and the team spent a month looking for an 'app bug'.

FCM on Android works through Google Play Services. For devices without GMS (Huawei, part of the Chinese market), Huawei Push Kit or a direct WebSocket is needed — a separate task. FCM supports data messages (handled in onMessageReceived) and notification messages (the system displays automatically if the app is in the background). Mixing them requires caution: if the notification block has a click_action but the deep link is not registered in the app, tapping the notification simply opens the main screen without navigation.

Why Segmentation Is the Foundation of Effective Push Notifications?

Sending to everyone indiscriminately quickly exhausts user loyalty. Personalized messages are clicked 3 times more often than bulk ones, and proper segmentation reduces churn by 25% (on one project it brought significant additional revenue per quarter). The cost of setting up segmentation in OneSignal or a custom backend depends on the complexity of filters.

Proper segmentation is built on several levels.

Topics are for broad categories: 'new promotions', 'order status updates'. User subscribes via FirebaseMessaging.getInstance().subscribeToTopic("orders"). Simple, but no flexible filtering.

Attribute-based segments — via OneSignal, Braze, or custom backend. We store in the user profile: language, device type, last activity, LTV segment. Notification goes only to those with last_active < 7_days and plan = premium. OneSignal allows building such filters in the interface without code.

Personalized — by specific device_token. It's important to store tokens correctly: the token updates on app reinstall, restoration from backup on a new phone, or resetting settings. On iOS, use UNUserNotificationCenter + didRegisterForRemoteNotificationsWithDeviceToken, save to backend on every launch, not just the first. Otherwise, after 3 months 30% of tokens in the database are outdated.

What Is Rich Push and How Does It Boost Conversion?

A standard notification with title and text is clicked less often than a rich push with image and action buttons — by 3 times. But implementing rich push is a separate task on each platform.

On iOS, rich content requires UNNotificationServiceExtension (to modify payload) and UNNotificationContentExtension (custom UI). The extension runs in a separate process with limited time and memory. If the extension crashes or exceeds the timeout, the system shows the original payload without media. A typical mistake is trying to load an image over HTTP (not HTTPS): ATS blocks the request, the extension silently fails, and the user sees a notification without an image.

On Android with API 26+, notifications are tied to NotificationChannel. If the channel is created with IMPORTANCE_LOW, sound and vibration are unavailable. Different notification types (transactional, marketing) should be in different channels so the user can disable marketing without losing order notifications. BigPictureStyle, MessagingStyle, InboxStyle are templates for expanded notifications. MessagingStyle with Person and avatars is the best choice for chats.

How to Track Delivery and Conversion of Push Notifications?

Sending a notification is half the work. It's important to know: was it delivered, opened, and did it lead to a target action.

FCM returns a MessageId on send, but does not guarantee a delivery callback — by design. For open tracking, custom logic is needed: on notification tap in onMessageReceived or via getInitialNotification() / onNotificationOpenedApp (OneSignal SDK), send an event to analytics with notification_id.

OneSignal provides built-in delivery and CTR analytics. For more detailed analysis — integrate with Amplitude or Mixpanel via webhook on open events. The budget for such a dashboard varies depending on event volume.

How We Implement Push Notifications: Typical Process

1. Audit current implementation — check token storage, update handling, notification types.
2. Design architecture — choose transport (FCM + APNs), segmentation layer (OneSignal/Braze/custom), personalization method.
3. Implementation — write registration code, inbound handling, rich push, deep linking.
4. Testing — send test campaigns, verify delivery on different devices, simulators, regions.
5. Monitoring and analytics — set up dashboard, open and conversion events.
6. Documentation and training — hand over operational materials to the team.

Typical stack: FCM + APNs at transport level, OneSignal or Firebase Notifications Composer for segmentation, custom backend for personalized event-based notifications. For large apps with >1M users, OneSignal has pricing limits — then we use Braze or a custom implementation on AWS SNS.

Timelines depend on complexity: basic FCM+APNs integration with transactional notifications — 1–2 weeks. A full system with segmentation, rich push, analytics, and A/B testing — 4–8 weeks. Order an audit of your current push infrastructure or get a consultation on implementing push notifications in your mobile app — we will contact you within a day and provide an accurate estimate.