You're welcome, and thank you for the comment. I noticed this as well; I'm definitely searching a way to make the vibration more noticeable. Someone else suggested abandoning the mobile phone platform altogether to make a more robust product in general. If not me, maybe Nest will do something like this with their smoke detectors. They're already connected to wifi, so it would just take a wifi-enabled vibrator do the same thing, perhaps more reliably. Still, it might be a while before every smoke detector is as smart as a Nest ;)