Indicate hydration level in another way

“Vessyl can even tell you whether you need to drink more water by displaying a vivid blue line that rises and falls dependent upon your hydration level. Vessyl calls this part of the technology “Pryme,” and it can be displayed independently on the cup itself, or within the app to show you not only how hydrated you are, but for how long you remained at optimal hydration levels. All of which coincides with the Vessyl mantra of empowering people to make better choices.”