Examine source code of DE Timer

{
  "manifest_version": 2,
  "version": "0.2.1",
  "author": "Dhiviya Rajan and Erin Meow",
  "name": "DE Timer",
  "description": "__MSG_description__",
  "default_locale": "en",
  "permissions": [
    "storage",
    "alarms",
    "notifications"
  ],
  "homepage_url": "https://add0n.com/alarm.html",
  "background": {
    "persistent": false,
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "data/icons/48.png"
  },
  "browser_action": {
    "default_popup": "data/popup/index.html"
  },
  "options_ui": {
    "page": "data/options/index.html"
  },
  "commands": {
    "open-interface": {
      "description": "Open the interface in a window"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{41744738-efe6-4b89-b819-a09fcd4cbf47}"
    }
  }
}