From their FAQ: If you have an iPhone 4S or iPhone 5, Lockitron will work even if the internet or power go out. And of course, you can always use your original

From their FAQ: If you have an iPhone 4S or iPhone 5, Lockitron will work even if the internet or power go out. And of course, you can always use your original key I guesss it also uses Bluetooth for manual unlock and not only for Sense.