DiDO CK18 0.96 inch Waterproof Smartwatch, Support Blood Pressure Monitoring / Sleep Monitoring / Pe worth to buy? Thanks for it if those of you who have purchased DiDO CK18 0.96 inch Waterproof Smartwatch, Support Blood Pressure Monitoring / Sleep Monitoring / Pe could share about what you think of the product. I would love any extra info, as it is quite pricey as $54.40 and I just want to know it is good before paying for it.