While several smartphones today have an IP rating for water and dust resistance, one would not dare to test the same by dunking an expensive smartphone underwater. So, an Android developer has created a free app that lets users test whether their IP-rated smartphones are still water-resistant or not.

Dubbed the Water Resistance Tester, the app is built by a developer named Raymond Wang and uses a smartphone’s barometric pressure sensor to test its water resistance. It basically measures the minute differences in physical pressure to determine whether the water-resistant seals in a smartphone are intact or not.

Once you open the app, it will ask users to leave their devices idle for a moment. The users are then required to put both their thumbs on two marked points on the screen and press down firmly.

Following this, the app measures the minute pressure differences with a varying degree of accuracy to test whether the water-prevention seals are intact or not.

Download Water Resistance Tester (Free)