Sounds like room for improvement: Shout "earthquake" through the phone's speakers (overriding any volume setting), flash "earthquake" on the screen (turning the

Sounds like room for improvement: Shout "earthquake" through the phone's speakers (overriding any volume setting), flash "earthquake" on the screen (turning the screen on if necessary, but if that takes a second, don't have it delay the sound output but do it in parallel), and especially without unlocking or opening the app.