Examine source code of Popup for Google Tasks

{
  "manifest_version": 2,
  "offline_enabled": false,
  "name": "Popup for Google Tasks",
  "description": "Opens Google Tasks in a popup window.",
  "version": "1.0.1",
  "author": "Jonah Lawrence",
  "browser_action": {
    "default_icon": "images/icon-128.png",
    "default_popup": "popup.html",
    "default_title": "Popup for Google Tasks"
  },
  "icons": {
    "128": "images/icon-128.png"
  },
  "permissions": [
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "popup-for-google-tasks@example.com"
    }
  }
}