Here is another smart tool that can make you a better swimmer. The Zwim is a pair of smart goggles that provides you with real-time data while swimming. It detects and calculates heart rate, laps, time, and calories. Thanks to this tool, you will be able to check your time while swimming to set the right pace.
Zwim comes with an accurate optical heart-rate sensor. It can show up to 4 data points on its display. After each session, the data can be synced to iOS or Android devices.[where to find it]