Build instructions here : https://www.instructables.com/ESP32-Balancing-Robot/

This is an app for controlling balancing robot. On the first startup, the robot will configure to AP(Access Point) mode with SSID "Balancing Robot" and password "12345678". Connect your WiFi to this AP. Once connection is established, open the App and should see telemetry data from the robot, including speed, voltage, power...etc, if not just press the Connect button to connect manually.

* Note that connecting to a WiFi without internet might not work on some devices.