Examine source code of Text Highlighter

{
  "manifest_version": 2,
  "name": "Text Highlighter",
  "version": "1.0",
  "description": "Highlight text on webpages.",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/highlight-48.png",
    "default_popup": "popup.html",
    "default_title": "Text Highlighter"
  },
  "icons": {
    "48": "icons/highlight-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8788a26b-e705-484e-a3cd-b29f4836f23a}"
    }
  }
}