The most common complaint about phone alarm apps is not that they are too quiet. It is that they worked in the test and then stayed silent later, when someone actually picked the phone up. Almost every time, the app did not break. The phone put it to sleep.
Why it happens
Android saves battery by pausing apps that run in the background. That is good for a game you forgot to close and bad for an alarm whose whole job is to wait. Many manufacturers add a second layer on top, with their own lists of apps to stop. An alarm can be armed, look armed, and have been paused for twenty minutes.
1. Run the twenty-second test
Before changing anything, prove the alarm itself works. In Shoo, tap Arm it, put the phone down, wait for the three-second countdown, and pick it up. If the siren fires, the alarm is fine and the problem is the phone’s battery settings. If it does not, email us with your phone model.
2. Set battery use to Unrestricted
This tells Android not to pause the app in the background.
3. Samsung: take it off Sleeping apps
Samsung phones keep a separate list of apps that are put to sleep, whatever Android’s own setting says. If Shoo is on it, remove it.
4. Make sure the siren is loud
Shoo plays on the alarm channel through the loudspeaker, so the silent switch and the volume keys do not quiet it. If the siren comes out of your earbuds instead, turn off “Media sound to earbuds” in your phone’s Bluetooth settings.
On iPhone
iOS does not have Android’s battery managers, but it also does not let apps relaunch themselves after a restart. Motion, pocket, charger, wrong-PIN and Wi-Fi triggers all work on iPhone; after a restart, Shoo reminds you to re-arm.
How to see it is awake
Most alarm apps give you no way to know. Shoo keeps a foreground service running and shows a heartbeat on the armed screen, “checked 3 s ago”, so you can see at a glance that it is still watching.