Examine source code of Gmail (Pin Tab)

{
  "name": "Gmail (Pin Tab)",
  "description": "Displays unread emails count and Switch to Gmail (Pin Tab) with a single click or a Hot Key (Alt+2)!",
  "version": "1.1resigned1",
  "manifest_version": 2,
  "permissions": [
    "*://*.mail.google.com/*",
    "storage",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icons/gmail-icon.png"
  },
  "browser_action": {
    "default_icon": "icons/gmail-icon.png",
    "default_title": "Switch to Gmail (Pin Tab)"
  },
  "options_ui": {
    "page": "options/options.html"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Alt+2"
      },
      "description": "Switch to Gmail (Pin Tab)"
    }
  },
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "*://mail.google.com/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{a0ae2323-ffbe-4680-a355-649639297c69}"
    }
  }
}