Examine source code of save-file-up-load.io

{
  "manifest_version": 2,
  "name": "save-file-up-load.io",
  "description": "save file to up-load.io, works on link or image",
  "version": "0.0.1.3",
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "id": "save-file-up-load.io@example.com"
    }
  },
  "icons": {
    "48": "icons/48.png"
  },
  "background": {
    "page": "background.html"
  },
  "permissions": [
    "<all_urls>",
    "tabs",
    "contextMenus",
    "notifications",
    "webNavigation"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://up-load.io/?op=upload_form"
      ],
      "js": [
        "js/upload_form.js"
      ]
    }
  ]
}