Examine source code of ListenLater.fm

{
  "manifest_version": 2,
  "name": "ListenLater.fm",
  "version": "1.1.2",
  "description": "A read-it-later service for your ears",
  "homepage_url": "https://www.listenlater.fm",
  "icons": {
    "48": "icons/ear-512.png"
  },
  "permissions": [
    "bookmarks",
    "tabs",
    "storage",
    "*://*/*"
  ],
  "browser_action": {
    "default_icon": "icons/ear-512.png",
    "default_title": "ListenLater.fm"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "listen-later-fm@listenlater.fm",
      "strict_min_version": "57.0a1"
    }
  }
}