Examine source code of SuperEmotes

{
  "manifest_version": 2,
  "description": "Create custom emotes and make them available in your Youtube comments and live chat today!",
  "name": "SuperEmotes",
  "permissions": [
    "https://api.superemotes.com/*",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "version": "1.4.1",
  "icons": {
    "16": "img/robot_16.png",
    "24": "img/robot_24.png",
    "32": "img/robot_32.png",
    "48": "img/robot_48.png"
  },
  "browser_action": {
    "default_popup": "/html/popup/popup.html"
  },
  "content_scripts": [
    {
      "run_at": "document_end",
      "js": [
        "js/reactions/reactions-constants.js",
        "js/content-scripts/message-handlers.js",
        "js/content-scripts/inject-utils.js",
        "js/content-scripts/injector.js"
      ],
      "matches": [
        "*://studio.youtube.com/*",
        "*://*.youtube.com/*",
        "*://*.facebook.com/*"
      ],
      "all_frames": true
    },
    {
      "js": [
        "js/constants/facebook/constants.js",
        "js/emotes-tray/facebook/emotes-tray.js",
        "js/content-scripts/facebook/mapper.js",
        "js/content-scripts/facebook/injector.js"
      ],
      "css": [
        "css/facebook/emotes-tray.css",
        "css/facebook/base.css"
      ],
      "matches": [
        "*://*.facebook.com/*"
      ]
    }
  ],
  "web_accessible_resources": [
    "js/svg/svg.js",
    "js/css-vars/themes-utils.js",
    "js/dashboard/dashboard.js",
    "js/dashboard/draggable-window.js",
    "js/emote-details/emote-details-hover-constants.js",
    "js/emote-details/emote-details-hover.js",
    "js/emotes-tray/comment-emotes-tray-constants.js",
    "js/emotes-tray/comment-emotes-tray.js",
    "js/emotes-tray/live-stream-emotes-tray-constants.js",
    "js/emotes-tray/live-stream-emotes-tray.js",
    "js/emotes-tray/emotes-tray-utils.js",
    "js/page-scripts/page-script-constants.js",
    "js/page-scripts/page-utils.js",
    "js/page-scripts/page-script.js",
    "js/page-scripts/comment-section.js",
    "js/page-scripts/live-stream.js",
    "js/page-scripts/mapper.js",
    "js/reactions/reactions-constants.js",
    "js/reactions/reactions-utils.js",
    "js/reactions/reactions.js",
    "js/tags/tags.js",
    "js/network/network-constants.js",
    "img/chevron_left.svg",
    "img/chevron_right.svg",
    "css/tags.css",
    "css/reactions.css",
    "css/live-stream-emotes-tray.css",
    "css/comment-emotes-tray.css",
    "css/popup.css",
    "css/dashboard.css",
    "css/youtubecontent.css",
    "css/themes/bools-dark.css",
    "css/themes/grape-lime-soda.css",
    "css/themes/ice-cool-blue.css",
    "css/themes/laser-beam-attack.css",
    "css/themes/peaches-n-cream.css",
    "css/live-stream-chat.css",
    "css/base.css",
    "js/page-scripts/facebook/page-script.js",
    "js/constants/facebook/constants.js",
    "js/emotes-tray/facebook/emotes-tray.js",
    "css/facebook/base.css"
  ]
}