Examine source code of Historify

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "permissions": [
    "storage",
    "tabs",
    "<all_urls>"
  ],
  "version": "1.4.2resigned1",
  "description": "__MSG_extensionDescription__",
  "homepage_url": "https://github.com/flosommerfeld/Historify",
  "author": "flosommerfeld",
  "icons": {
    "96": "icons/icon_96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_script.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "background": {
    "scripts": [
      "background_script.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/icon_96.png",
    "default_title": "Historify"
  },
  "applications": {
    "gecko": {
      "id": "historify_flosommerfeld@example.com",
      "strict_min_version": "42.0"
    }
  },
  "default_locale": "en"
}