Following the announcement in September, the Apple Watch Nike+ is now available for purchase. Billed as an athlete's perfect running partner, the watch features an easy-to-read face and a built-in GPS to track your runs, as well as lightweight, breathable band for comfort. Additional benefits include a heart rate sensor, accelerometer, and gyroscope; water-resistance to 50 meters; and up to 18 hours of battery life. The Apple Watch Nike+ is offered in four colors and two sizes, 38mm ($369) and 42mm ($399). Get yours now at nike.com.