Copy control.html and control.js and the whole images folder into your own webapp directory. Create api_key.js (as shown below). Tell users to go to control.html (whatever its URL is in the case of your webapp) on Google Chrome on their mobile phone and to hold the phone horizontally.
If you used DStrike in your project and want to be nice, please credit me. If you don't want to be nice, then don't credit me.
Sign up for Ably. Create a new app. In the dashboard, select your app and view the API key. Give the API key permissions to push and subscribe. Copy the API key into a file called api_key.js. Put the file into this repository (cloned locally). In the file, type const API_KEY = "Whatever your API key is";.