Examine source code of Mood Journal

{
  "manifest_version": 2,
  "name": "Mood Journal",
  "version": "1.0",
  "description": "Quickly record your mood & short notes. Store locally and export history as CSV.",
  "icons": {
    "48": "mood_icon.png"
  },
  "browser_action": {
    "default_popup": "index.html",
    "default_title": "Mood Journal"
  },
  "permissions": [],
  "browser_specific_settings": {
    "gecko": {
      "id": "{4667b75a-ba6c-43a2-bc59-3d3c082c7cbe}"
    }
  }
}