Examine source code of External Video Player

{
  "manifest_version": 2,
  "name": "External Video Player",
  "version": "2.0.2resigned1",
  "description": "Open HTML5 videos on Android with any video player like VLC, MxPlayer, etc.",
  "applications": {
    "gecko": {
      "id": "android.external.player@albertogasparin.it"
    }
  },
  "permissions": [
    "activeTab",
    "<all_urls>"
  ],
  "browser_action": {
    "default_icon": "external-video-player.svg",
    "default_title": "Play video externally"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}