* important note: All of smartphones do not have all of sensors. Some of results might be not-calculated, that is possible situation and you will see block icon on sensor icons. That does mean; Your device does not have these sensor(s).
* Easily you can check your heart rate, environmental temperature, humidity, air pressure, altitude and the angle between the magnetic north pole and your device direction for the location which you are in.
* Heart rate sensors mostly on the back side of the device, together with rear camera flash or near. If you have a health problem with your heart, we advice to you professional care.
* Smart phones do not have a built-in altimeter and about that altitude value is calculating by air pressure (from barometer data), it might be not correct result always.
*** And we are open for any help issues about the app, please reach us for any query.