Bar Psi is a free Android app developed by raincontinues that provides a simple way to convert between pressure units. The app's main focus is on converting between bar and psi units, but it also includes other units such as kg/cm2, mbar, Pa, kPa, MPa, inH2O, mmHg, N/m2, hPa, atm, mmH2O, inHg, mH2O, Torr, ftH2O, oz/in2, g/cm2, cmH2O, cmHg, at, mTorr, and dyn/cm2.

The app's interface is straightforward and user-friendly. You can easily select the input and output units and enter the value you want to convert. The app instantly provides you with the converted value. The app also has a history feature that keeps track of your previous conversions.

Overall, Bar Psi is a useful app for anyone who needs to convert pressure units regularly. Its simple interface and wide range of supported units make it a handy tool for both personal and professional use.