MotoAnswer
Unfortunately, not all smartphones offer the ability to automatically answer incoming calls while you're driving or when you can't use your hands.
This feature can be extremely useful in the case of us bikers who travel with a intercom or a headset wired into the helmet and we can not (or do not want to) use the hand to respond.
MotoAnswer can also help you when you are in-vehicle and you want all incoming calls answered by the loudspeaker or just when the headphones are connected.