Examine source code of instakko

{
  "manifest_version": 2,
  "version": "1.2.73",
  "name": "instakko",
  "description": "akko is cute edition // general public edition",
  "author": "St. Lain",
  "permissions": [
    "downloads",
    "storage"
  ],
  "background": {
    "scripts": [
      "js/instakko_background.js"
    ]
  },
  "icons": {
    "16": "icons/instakko_icon_16.png",
    "32": "icons/instakko_icon_32.png",
    "48": "icons/instakko_icon_48.png",
    "64": "icons/instakko_icon_64.png",
    "128": "icons/instakko_icon_128.png",
    "256": "icons/instakko_icon_256.png"
  },
  "web_accessible_resources": [
    "css/instakko.css",
    "icons/instakko_icon_256.png",
    "icons/instakko_icon_128.png",
    "icons/instakko_icon_64.png",
    "icons/instakko_icon_48.png",
    "icons/instakko_icon_32.png",
    "icons/instakko_icon_16.png",
    "icons/instakko_dl_multi.svg",
    "icons/instakko_dl_single.svg",
    "icons/instakko_dl_single_white.svg",
    "js/instakko_background.js",
    "js/instakko_main.js"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://www.instagram.com/*"
      ],
      "js": [
        "js/instakko_main.js"
      ],
      "css": [
        "css/instakko.css"
      ],
      "run_at": "document_start"
    }
  ],
  "options_ui": {
    "page": "settings/settings.html"
  },
  "applications": {
    "gecko": {
      "id": "instakko@contoso"
    }
  }
}