Three minutes to find out whether your alarm app will ring tomorrow

A third-party alarm app rings through the Ring/Silent switch and Focus on iPhone only if it is built on Apple’s AlarmKit framework, which requires iOS 26 or later and the user’s permission. Android has no equivalent switch problem, but a third-party alarm can still fail there if the app lacks the Alarms & reminders permission or the phone’s battery manager has put it to sleep.

DontSnooze is an alarm app where friends see whether you woke up, so it has to clear these same hurdles, and the safest rule applies to it too: keep a built-in Clock alarm a few minutes later as a backup.

What does Apple say AlarmKit does?

In WWDC25 session 230, Apple says of an AlarmKit alarm: “When it fires, the alert breaks through the silent mode and the current focus.” The same session says people must consent first, and that they can change that consent in Settings at any time. AlarmKit’s reference page lists availability as iOS 26.0 and later.

Apple also says alarms “are not a replacement for other prominent notifications, like critical alerts or time-sensitive notifications.” (The critical-alert entitlement is a separate, rarely granted route.) An app that has not adopted AlarmKit is sending ordinary notifications, and those follow Focus rules. Apple’s own Clock alarms ignore the Ring/Silent switch and Do Not Disturb, according to its alarm support page.

Which steps test an alarm app?

1. Set a test alarm three minutes ahead in the third-party app. Say yes to any prompt.
2. Recreate the worst night. Silent switch on, or a Focus on, screen locked. Android: just lock it.
3. iPhone, if it stayed quiet: open the app’s page in Settings and turn on any alarm or notification permission that is off. Then see the Focus allow-list fix.
4. Android: Settings, Apps, the app, Alarms & reminders, on. Google’s documentation says the SCHEDULE_EXACT_ALARM permission “is not pre-granted to fresh installs of apps targeting Android 13” or higher, and that a user can revoke it.
5. Android: set the app’s battery usage to unrestricted. Samsung’s own lists are covered below.

Why would the alarm vanish after a restart or restore?

Android’s alarm documentation says “by default, all alarms are canceled when a device shuts down.” An app can reschedule on boot, but Google notes that works only if the user has launched the app at least once. So open the app after any reboot.

Moving to a new phone has its own trap. Google says that if app data is restored onto an Android 14 device, the exact-alarm permission “will be denied on the new device.” Recheck step 4 after every migration.

Apps that qualify can instead declare USE_EXACT_ALARM, which Google says is granted automatically and cannot be revoked. Google limits it to “limited use cases,” so a user cannot count on it.

What do Samsung and other makers add?

The community site Don’t Kill My App says Samsung puts an app to sleep after 3 days unused by default, and that after that “alarms will not work anymore.” Its fix is to remove the app from Sleeping apps and Deep sleeping apps. The deeper walkthrough is in the Doze and battery-optimization guide.

Nobody can verify every app on every phone. A native Clock alarm, set ten minutes after the main one, costs nothing and covers whichever failure the test missed.