Examine source code of Screen snipe

{
  "manifest_version": 2,
  "name": "Dark Mode",
  "version": "1.0",
  "description": "Let's you take screen shots",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_title": "Screen Snipe"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{53830215-ed10-4407-ae62-dcc3f24abd70}"
    }
  }
}