If you are in the market for a new smartphone, the Samsung Galaxy S5 is one of the more popular new choices on the market. An interesting hidden feature has been discovered on the Galaxy S5, that function lets parents use the phone as a baby monitor. The feature is called the baby crying detector and it does what you expect. When the smartphone is left by the baby and the baby cries; the S5 will vibrate and alert the parent.
For it to function the GS5 has to be paired to a Galaxy Gear smartwatch and to be left within 1 meter of the baby in a room with no background noise. Presumably, that means something like a fan or one of those noisemaker things to calm a fussy baby will interfere with the feature.
Samsung also warns that the feature should not be a substitute for adult care. Most new parents develop a hypersensitivity to baby crying that has them running to the baby's room at every little whimper for the first few months. If you are heavy sleeping parent this might be a cool feature for you. That is assuming you can be without your phone around the house long enough to leave it by the baby.
If you have somehow missed the coverage of the Galaxy S5 on SlashGear, you can learn all about it here.