Examine source code of FindBox

{
  "manifest_version": 2,
  "name": "FindBox",
  "description": "",
  "version": "1.0.7",
  "icons": {
    "48": "img/lupe48x48blau.png"
  },
  "browser_action": {
    "browser_style": true,
    "default_popup": "popup/popup.html",
    "default_icon": "img/lupe48x48grau.png",
    "default_title": "FindBox"
  },
  "background": {
    "scripts": [
      "main.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://link-to.net/*",
        "https://linkvertise.com/*"
      ],
      "all_frames": true,
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "default_locale": "en",
  "permissions": [
    "https://link-to.net/*",
    "https://linkvertise.com/*",
    "contextMenus",
    "tabs",
    "webRequest",
    "<all_urls>",
    "storage"
  ]
}