I was really excited when I saw I was getting this product to try. What a great concept! A patch that monitors my hydration, how cool! Nope, what a flop. I was so disappointed. The patch itself was easy to apply and stayed in place, it didn’t irritate my skin or anything like that. I was sweating like crazy but nothing was happening, so I touched it to make sure it was securely on…that’s when the lines started to fill up and also leak out the edges leaving orange coloring on my arm around the patch. I’m regards to the app…it is confusing. I don’t need to plan a workout or a hike, and I don’t want to put in a workout I already did. I want it to monitor in current time. Also, this patch doesn’t work well above 95° per the app and won’t let you select a temp above 99° - it errored out because I live in Arizona and it’s still above 100° even in September. It was more hassle than the product is worth. I think it has serious potential, but right now…this just isn’t it.