While the Snapalarm doesn't improve on the functionality of smoke detectors, it does improve on the form. Normally to install a smoke detector, you need to first drill a hole into the wall or ceiling and then attach the unit with a couple of screws. As a result most people only have a single smoke detector installed in their home which can be dangerous depending on how big your place is and where the device is installed.
The Snapalarm is designed to be easier to install than a standard smoke detector. The device opens like a clamshell allowing it to be fastened to the cord or chain of a hanging pendant lamp which is ideal given the proximity of these lights to the ceiling. And as an added safety feature the halves of the alarm can't be closed if a working battery has not been installed.
Click this link to learn more about the Snapalarm from their website: http://www.snapalarm.com.