Create an (repetitive high pitch) Alarm on a remote trigger when App is not running (iphone/android) just like Find My iPhone

Question

I would like to cause an alarm on a remote iphone/android device when the app is running or not running.

How do I achieve it ?

I can only think of Whatsapp/S

Answer 1

For iOS, you will need a server to deliver a push notification to your app, where the notification references a custom audio alert to be played. The audio alert has to be included within the app's bundle as stated in Apple docs.

This alert can't be longer than 30 seconds. If you want the alert to be played longer, you can send send another push notification times roughly 30-seconds after and stop sending the alert when a) user open the app or b) you've reached the maximum threshold.

It's generally not good practise to send multiple notification containing the same payload, unless there is a good reason.

I would suggest splitting up this question into two: one for iOS, and another for Android.