Examine source code of Itemsy

{
  "name": "Itemsy",
  "short_name": "Itemsy",
  "version": "0.0.0.3",
  "description": "Turn content saved for later into a beautiful personal newsletter. Follow interesting people to read what they read.",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "images/logo16.png",
      "32": "images/logo32.png",
      "48": "images/logo48.png",
      "128": "images/logo128.png"
    }
  },
  "icons": {
    "16": "images/logo16.png",
    "32": "images/logo32.png",
    "48": "images/logo48.png",
    "128": "images/logo128.png"
  },
  "manifest_version": 2,
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "windows": "Shift+Ctrl+I",
        "mac": "Shift+Command+I",
        "chromeos": "Shift+Ctrl+I",
        "linux": "Shift+Ctrl+I"
      }
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "addon@itemsy.com"
    }
  }
}