The EKG test monitor appears to work very well, although I have my suspicions of if this unit truly checks your heart accurately. I learned the hard way how to trip it to show tachycardia when in reality it's not. It doesn't say in the book NOT to check your heart with a raised heart rate. In my mind I thought checking it immediately after working out would be a good thing. Nowhere in the book could I find information of not checking it when your heart rate is up. A lady was kind enough to call me when I put a message in through the app. Very awesome to have a real phone call addressing this. I told her this unit should be set to 30 second tests by default as you can only change it with the app. It is set to 10 seconds out of the box. Presuming it truly does work to see your hearts real activity it is a good thing to have. To me seeing I have Tachycardia that I truly don't have because of raised heart rate working out it's not smart enough to see the difference. Why can't it see I have a healthy heart still? There are 4 ways to check and of them I truly like the chest method as I feel it's best to check it close to your heart, but the book doesn't say anything about if and what method is most accurate at all. The unit works very simply and very easy to use. The app is a bit odd, and I had some issues finding things within it but it does work well. It syncs well and does work fine, but I feel it needs a bit of design/location of things reworking. For what it is I do recommend it as it may save a life!