Mood-changing wearables are nothing new. We have covered a bunch of them here in the past. doppel is a smart gadget that uses a pulse you feel on your wrist to get you more alert or relaxed. You can use the slow rhythm to stay calm or increase it to become more focused. The effect is similar to listening to an upbeat or slow song.
doppel is water and sweat resistant. It connects to your smartphone via Bluetooth. Expected to ship in March 2017.[where to get it]