SMA-B3 Fitness Tracker 0.96 inch Bluetooth Smart Bracelet, IP67 Waterproof, Support Activity Traker worth to buy? Thanks for it if those of you who have purchased SMA-B3 Fitness Tracker 0.96 inch Bluetooth Smart Bracelet, IP67 Waterproof, Support Activity Traker could share about what you think of the product. I would love any extra info, as it is quite pricey as $37.70 and I just want to know it is good before paying for it.