A lot of the Samsung Galaxy smartphones are water-resistant. But in some cases, as the phone ages, the water resistance capability goes down by a lot. This app can tell you if your phone still has that capability.
Though you may think that the only way to test this is to dunk the phone underwater. There are apps for everything, and this app named Water Resistance Tester app can do what it says it can do.
It relies on the device barometric sensor to predict what the water-resistance level is without dunking the phone underwater.
When starting the app you will be prompted to press firmly on both sides of the display. This concept does work, as if the SIM card was removed while it is testing, the result will come up as a 0.
Now even the developer doubts the apps capabillity, and on the same Samsung device, a result was positive, and another negative.
You can download it from the Play Store here.