XANES H28 Single Touch Waterproof Smart Watch spO2 Monitor Fitness Sports Bracelet worth to buy? Thanks for it if those of you who have purchased XANES H28 Single Touch Waterproof Smart Watch spO2 Monitor Fitness Sports Bracelet could share about what you think of the product. I would love any extra info, as it is quite pricey as $37.22 and I just want to know it is good before paying for it.