Here is a Bluetooth watch with its own spy earpiece set. It wirelessly connects to your smartphone and transfers voice to your earpiece. The Bluetooth Watch has a built-in amplifier, so you can listen from within 20cm range. The watch has a LED indicator, a multi-function button, and USB charging.
You can use the Bluetooth watch for hands-free phone communication. It provides you with 4 hours of talk time on a full charge. This can be yours for $90.