Examine source code of RegexKit

{
  "manifest_version": 2,
  "name": "RegexKit",
  "version": "1.0.4",
  "description": "simple regex tool for development and testing.",
  "homepage_url": "https://github.com/cherrimon/RegexKit",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "96": "icons/icon96.png",
    "192": "icons/icon192.png",
    "512": "icons/icon512.png"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/icon32.png",
    "default_title": "RegexKit",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "js/content.js"
      ]
    }
  ]
}