Examine source code of Web Paint

{
  "name": "Web Paint",
  "version": "1.2.7resigned1",
  "manifest_version": 2,
  "description": "Draw shapes, lines, and add text to live web pages and take screenshot.",
  "background": {
    "page": "Background.html"
  },
  "browser_action": {
    "default_title": "Web Paint",
    "default_icon": "images/icon38.png"
  },
  "icons": {
    "16": "images/icon16.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "permissions": [
    "tabs",
    "activeTab",
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "jid1-0dhOSYKGj326og@jetpack"
    }
  }
}