Examine source code of Imagus mod

{
  "author": "Deathamns,TFW",
  "background": {
    "page": "background.html",
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "includes/app.js"
      ],
      "run_at": "document_start",
      "all_frames": true
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "includes/content.js"
      ],
      "run_at": "document_end",
      "all_frames": true
    },
    {
      "matches": [
        "https://*/search*"
      ],
      "include_globs": [
        "https://www.google.*/search*"
      ],
      "js": [
        "js/sp_gim.js"
      ],
      "run_at": "document_idle"
    },
    {
      "matches": [
        "https://duckduckgo.com/*"
      ],
      "css": [
        "css/sp_ddg.css"
      ]
    }
  ],
  "default_locale": "en",
  "description": "With a simple mouse-over you can enlarge and display images/videos from links. Now with optional permissions, more features.",
  "homepage_url": "https://www.reddit.com/r/Imagus",
  "browser_action": {
    "default_icon": {
      "18": "icon-18.png",
      "128": "icon.png"
    },
    "default_title": "Imagus mod v0.10.15\nclick to toggle on/off\nshift click to open options page"
  },
  "icons": {
    "18": "icon-18.png",
    "128": "icon.png"
  },
  "manifest_version": 2,
  "name": "Imagus mod",
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "permissions": [
    "*://*/*",
    "storage",
    "menus"
  ],
  "optional_permissions": [
    "downloads",
    "history"
  ],
  "version": "0.10.15",
  "browser_specific_settings": {
    "gecko": {
      "id": "{6833a9cb-d329-4d96-a062-76b1b663cd2c}"
    }
  }
}