RiverSong Global via Amazon offers its RiverSong WaveFit Fitness Tracker and Heart Rate Monitor Smart Bracelet in Black for $29.99. Coupon code "GWHZC5SN" drops it to $23.99. With free shipping, that's $6 off and the lowest price we could find. Features include a 0.91" OLED touchscreen display, Bluetooth 4.0, fitness and sleep tracking, 24-hour heart rate monitor, sedentary reminder, smartphone notifications, time and date display, TPU strap, and rechargeable Li-po battery with up to a 4-day life. It's compatible with Android 4.4 and above and iOS 8.0 and above.