Smart scales are vital for modern, health-conscious people. Connected smart scales can track weight changes over Bluetooth and Wi-Fi to a cloud service. With the right data, these services can calculate your body mass index and body fat index. Heart rate monitoring and ambient air quality can also be monitored depending on the model. Though most connected scales are built for tracking human weight, there are several that track the weight of food you're preparing to ensure healthy portion control. Major players in this space include Fitbit and Withings, but it's a burgeoning sector with new players coming in every day.