The application searches an I2C bus to find a light sensor, a pressure sensor, a humidity sensor, and a temperature sensor. After enumerating the available sensors, it will show a carousel of measurements on the LCD.
For boards with a UEXT socket:
On everything else:
You can use a SenseCore with a CorePressure module and CoreLight module, for instance. Or you can use a Jee Labs plug shield with some sensors that they offer. Or you can plug both of them in at once, if you really want to.