A free program for Android, by Ray W.

Water resistance seals of phones can be compromised with drops and device aging, so it’s good to know if it’s still intact. Water Resistance Tester allows users to check the seals of their phone using its built-in barometer. With just a few taps, you will be able to see if your phone’s water resistance seal is still good. 

Water Resistance Tester comes with a simple, clean, and user-friendly interface. It does not require complex technical knowledge to access it.

Unfortunately, if your phone does not have a built-in barometer, the app will not work. Your phone must have one for the app to function.