It’s a security feature for Arduino. User is required to input the unlock pattern before remotely controlling/monitoring Arduino.

Introduction
You may be familiar with the unlock pattern when you access your phone. Now this feature is available on Arduino. It prevents the unauthorized people from controlling/monitoring Arduino.

User can freely re-use the code in this project for other application. For the sake of simplicity, I takes the servo motor controlling as an example.

This idea originates from two project, which is written for PHPoC platform:

https://www.hackster.io/iot_lover/web-based-pattern-unlock-for-iot-device-aeaf44.
https://forum.phpoc.com/articles/tutorials/350-servo-motor-controlling-servo-motor-via-websocket-with-graphic-ui
I adapt them for Arduino.

In this project, I used PHPoC WiFi Shield to connect Arduino to Internet because:

PHPoC Shield supports websocket, which is convenient for this project.
PHPoC Shield has a dedicated embedded web server, allowing to store the embedded web application on the shield.
PHPoC Shield has some built-in web applications that lets user uses embedded web application to control/monitoring Arduino without requiring any knowledge of web programming.

Also, PHPoC shield allows the users who can program web application to develop their own web application and store it on PHPoC Shield.”

Link