Examine source code of LibreTimer

{
  "version": "0.1.2",
  "manifest_version": 2,
  "default_locale": "en",
  "permissions": [
    "storage",
    "alarms"
  ],
  "name": "__MSG_chrome_extension_name__",
  "homepage_url": "https://github.com/Nudin/timer-webext",
  "description": "__MSG_chrome_extension_description__",
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "data/popup/popup.html",
    "default_title": "__MSG_browser_action_title__",
    "default_icon": {
      "16": "data/icons/16.png",
      "32": "data/icons/32.png",
      "48": "data/icons/48.png",
      "64": "data/icons/64.png"
    }
  },
  "icons": {
    "16": "data/icons/16.png",
    "32": "data/icons/32.png",
    "48": "data/icons/48.png",
    "64": "data/icons/64.png",
    "128": "data/icons/128.png"
  }
}