Measure The Surroundings is a small tool that uses all available hardware I could find in my phone which is a Samsung Galaxy S4 and S8.
If you try it on another brand, measurements greatly depends on how many sensors your phone has.
It Measures:
EMF, Temperature, Proximity, Geomagnetic, Acceleration, Rotation, Gyroscope, Azimuth, Pressure, Humidity, Gravity, Light, Linear Acceleration and GPS position.
It also fetches the weather at the Long and Lat position that the GPS is retrieving.
It calculates meters above the sea, dew point, absolute humidity.
It uses Geo-Location to retrieve the address at current GPS position.
See this as a fun app to use.
No data, location, or any other information is read or sent from this app to any server or person.
I have the highest respect for your integrity.

Also don't use the app for measuring important data for aviation or other situations where the risk of people to be harmed, do use professional equipment for such purposes.

Have fun.

If you find any strange behavior, don't hesitate to send me a mail.
/Wiken :)