This board comes with everything you could potentially need:
ADC - ADS1115 with 4 channels
DAC - MCP4728 with 4 channels
Power meter - INA260
Oled port
LED Driver/PWM driver - PCA9685 adds 8 pins
GPIO expander - MCP23017 adds 16 pins
Touch sensor - AT42QT with 6 pins and 2 pads built into the board
A boost converter with a negative charge pump?
esp8266 port
the Arduino Leonardo as the brains
And the board itself


For the most part it doesn't use much from the original Arduino board past Digital pins D6-D13.