F21 1.14 inch TFT Color Screen Smart Bracelet, Support Call Reminder/ Heart Rate Monitoring /Blood P worth to buy? Thanks for it if those of you who have purchased F21 1.14 inch TFT Color Screen Smart Bracelet, Support Call Reminder/ Heart Rate Monitoring /Blood P could share about what you think of the product. I would love any extra info, as it is quite pricey as $32.40 and I just want to know it is good before paying for it.