It includes 3x controlled 5V - GND connector (eg. for controlling relays), 12 GPIO pins, power connectors, SD card, USB and external power supply (5V), USB-UART bridge, some misc stuff and prototype of ESP32-USB ARM bridge. Originally designed to be IoT device to monitor and control small aquaponics system.
Rev 4 is alive. Today I have soldered new version of the board, arm bridge received it's own crystal and now it is 100% separated from sd card and can be used simultaneously. Also it has its own 4 bit gpio port and led. TVS diode caused too much drop on usb power so I decided to use it in reverse polarity to ground still being reasonable protection for overvoltage and reverse current. Next step is to create fully arm bridge example - usb keyboard host and simple text browser on ILI9341 display.