Examine source code of Linkognito

{
  "manifest_version": 2,
  "name": "Linkognito",
  "version": "1.7resigned1",
  "description": "Open links in incognito mode",
  "icons": {
    "48": "img/icon.png",
    "96": "img/icon@2x.png",
    "128": "img/icon-128px.png"
  },
  "applications": {
    "gecko": {
      "id": "linkognito@gandi.net"
    }
  },
  "background": {
    "scripts": [
      "src/background/index.js"
    ]
  },
  "permissions": [
    "tabs"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://*/*",
        "http://*/*",
        "file://*/*"
      ],
      "js": [
        "src/linkognito.js"
      ],
      "run_at": "document_end",
      "all_frames": true
    }
  ]
}