Meet Sgnl: a smart strap that lets you make calls by touching your ear with your fingertip. You will be able to answer calls through the built-in microphone. The strap is compatible with Apple Watch, Samsung Gear, Pebble Time, and regular watches.
It has a body conduction unit and communicates with your phone through Bluetooth. When you put your finger to your ear, it will transmit the sound and blocks out background noise. This project by Samsung spin-off Innomdle Lab is already killing it on Kickstarter.