Examine source code of To-Doer

{
  "manifest_version": 2,
  "name": "To-Doer",
  "version": "1.0",
  "description": "Stay organized and boost productivity with To-Doer: your simple task management tool.",
  "short_description": "A simple to-do list extension",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon16.png",
      "48": "icon48.png",
      "128": "icon128.png"
    }
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{bc938e2d-a094-4a10-8cc3-937d177ddc50}"
    }
  }
}