Pokemon Go Plus is a wearable device that links to your smartphone through Bluetooth and informs you when a for Pokemon is nearby as you travel the streets.
Whenever a Pokemon is nearby, an LED light will flash and the device will mildly vibrate. You can then check out which for Pokemon it is by looking on your phone and using the app, or when the LED flashes and the device vibrates, you can press the button to throw a Pokeball.
You will then get another notification if you caught it. Collect for Poke Balls,for Berries, and for Pokemon Eggs without having to look at your smart phone.