Examine source code of Remove.bg

{
  "manifest_version": 2,
  "name": "Remove.bg",
  "version": "0.1.0",
  "description": "Right click and Save wth Background Removed",
  "icons": {
    "48": "icons/removebg-firefox-48.png"
  },
  "permissions": [
    "contextMenus",
    "storage",
    "notifications"
  ],
  "background": {
    "scripts": [
      "removebg-firefox.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "browser_action": {
    "default_popup": "options.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "remove-bg@im-at.work",
      "strict_min_version": "42.0"
    }
  }
}