by Anton Weber
Disable annoying startup sounds!
Silent Boot mutes your phone on shutdown to keep it silent on boot and restores previous volume settings after startup is complete.
Please note: This workaround does not apply to all phones.
shut your phone up! — This app is a great, simple way to disable any sounds your phone makes on startup. That way you can clandestinely reboot your phone if necessary (though it does not remove sounds that may occur on shutdown).