M4 Men's Smart Watch Heart Rate Blood Pressure Monitoring Fitness Tracker Bluetooth Sports Waterproo worth to buy? Thanks for it if those of you who have purchased M4 Men's Smart Watch Heart Rate Blood Pressure Monitoring Fitness Tracker Bluetooth Sports Waterproo could share about what you think of the product. I would love any extra info, as it is quite pricey as $93.99 and I just want to know it is good before paying for it.