Examine source code of Gratitude Prompt

{
  "manifest_version": 2,
  "name": "Gratitude Prompt",
  "version": "1.0",
  "description": "Get a gratitude prompt in a new tab and jot down what you're thankful for.",
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "permissions": [
    "storage"
  ],
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6a631393-009d-47b7-a366-cf7a20fdbe7a}"
    }
  }
}