Mobile phone apps that promote mental health through meditation and breathwork are gaining popularity. Here’s a device that complements an app to take the activity to the next level. Muse, an EEG (electroencephalogram) measuring headband-device, passively senses brain activity by tracking electrical impulses. It also facilitates meditation by converting brainwaves into “weather sounds” — an overactive mind generates stormy weather noises whereas a calm mind results in peaceful weather. By letting you track when your focus shifts through these noises, the headband brings attention back to the breath, thus aiding meditation. The product has received rave