Overall, I'm very happy with this device. It comes with everything needed to record ECG's - device, cable, spare pads, case. I'm a retired paramedic & RN, with 30+ years of experience taking and reading mostly 2-lead and 12-lead ECG's. So far, all interpretations provided by the app match up with my own professional opinion. (This device only records in leads I and II, but the app interpretation is similar to what I've seen on 12-lead devices.)
With that being said, this device must be used with an app (free on Google Play). The app wasn't too difficult to navigate, though there are some minor issues they could fix to make it a little more user-friendly. After running a 5-minute check using the pads, I was impressed with both the clarity of the ECG tracing and the interpretation. You can assign 2 individual users on the app, plus the option to check others not assigned. All ECG's can be saved and printed.
You can also do a faster ECG check by just holding the device. However, there was a lot more artifact present in these tracings. It was good for a quick look, particularly if you're just wanting to check rhythm regularity or determine if a "missed beat" was a PVC. If you want a more detailed view, the pads should be used.
I purchased this as my wife and I are traveling more, particularly to remote areas. This device is just another tool to help us determine if a trip should be cut short to search for more definitive medical care. It will also be helpful to show a MD a good tracing of any odd heartbeats that may sporadically occur.