F2 1.44 inches Color Screen Smart Bracelet Bluetooth 4.0,Support Information Push/Heart Rate Monitor worth to buy? Thanks for it if those of you who have purchased F2 1.44 inches Color Screen Smart Bracelet Bluetooth 4.0,Support Information Push/Heart Rate Monitor could share about what you think of the product. I would love any extra info, as it is quite pricey as $31.40 and I just want to know it is good before paying for it.