Simply pour in your favorite hot beverage and let the Ember Mug² do the rest! The LED light will indicate when your Ember is trying to reach the perfect temperature and when it’s ready for you to enjoy. You can also connect the Ember to your smartphone via Bluetooth, by downloading the Ember app. The Ember app will allow you to adjust your preferred temperature, add preset temperatures, and notify you when your beverage has hit your perfect drinking temperature.