Examine source code of TredoList

{
  "manifest_version": 2,
  "name": "TredoList",
  "applications": {
    "gecko": {
      "id": "tredolist-firefox@netismic.com"
    }
  },
  "description": "TredoList turns Trello into a convenient todolist tool, by introducing new list layouts and dynamic color themes.",
  "version": "1.0.0",
  "author": "Olivier Cado",
  "icons": {
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "background": {
    "page": "background.html",
    "persistent": true
  },
  "permissions": [
    "*://trello.com/b/*",
    "tabs",
    "storage"
  ],
  "web_accessible_resources": [
    "css/layout.css",
    "css/theme-.css",
    "css/theme-bright.css",
    "css/theme-pastel.css",
    "css/theme-dark.css"
  ],
  "page_action": {
    "default_title": "Tredolist",
    "default_popup": "config.html",
    "default_icon": {
      "19": "icon48.png",
      "38": "icon48.png",
      "48": "icon48.png"
    }
  },
  "-ms-preload": {
    "backgroundScript": "backgroundScriptsAPIBridge.js",
    "contentScript": "contentScriptsAPIBridge.js"
  }
}