This app will help you test whether the IP67/IP68 water-resistance seals on your phone are still intact by using the barometer built in to your phone. Do note that the seals can become compromised with drops and device aging - keep your phone away from all liquids!
Note:
If your phone does not have a built-in barometer, it cannot be supported. Having a barometer built-in to the phone is required for the core functionality of this app, and no app can install physically missing hardware.