Meet the Nix Hydration Biosensor: a smart gadget that provides real-time sweat analysis. It consists of a pod that can be reused and a sweat patch that collects sweat for analysis. The device continuously monitors fluid and electrolyte losses when you are sweating. The pod weighs less than 0.5 ounces and lasts up to 36 hours on battery.
The Nix app is available for iOS devices. It provides you with hydration notifications and post-work hydration summaries. The Nix Hydration Biosensor is Apple Watch and Garmin friendly. It combines with your phone to let you know how much to drink.