iphone only app
it uses the iphone dialer to dial out the phone number that you want dialed incase a sound is detected, though in many cases you wouldnt want to use the default dialer, this app will be #1 if it can dial-out using facetime OR google hangout OR skype, that will allow it to be used on ipad also.
itsALemon about
Babyphone (Babyfon), v1.9