Android smartphone manufacturers always give an IP rating or with the devices, they sell if they pass a series of tests. Android developers are coming up with tools you didn't know where possible, for example, this little app called Water Resistance Tester claims to tell you if your phone's water resistance is still working without water.
That way, you don't have to submerge your device in water and damage it to see if it can prevent liquids from seeping into the case. The app is free to download from the Google Play Store, and the developer uses data from the barometric pressure sensor now built into most flagships as an aid in vertical positioning. The nuances of the device's barometer can help test, with varying degrees of accuracy, whether the intrusion protection messages built into a phone with an IP67 or IP68 rating are still working.
The test asks the user to leave the phone alone for a moment, and then press down firmly across two points on the screen. By measuring the pressure differences, he says, he can tell if the protections are still reliable. It should work across any IP-rated phone and can adapt to physical changes.
The developer of an Android application does not make any guarantees in the application, and the results will not affect a company that decides that it does not want to honor the guarantee. Google Play Store reviews indicate that phones without an IP rating give a negative result. And those that have protection but have a screen repair report, the protection messages no longer work. The developer says it created the app to help people check the condition of their device's waterproof sealant after a repair.
It is noteworthy that this application is not the first of its kind. But it seems that some of the water-resistance testing apps in the Google Play Store have been designed for older phones with a different style of waterproofing than what is used in phones today. It may not work accurately now.
Regardless of the results, you should be careful when handling water with any old phone. And waterproof devices become more vulnerable as phones age.