Examine source code of CircleLoop

{
  "manifest_version": 2,
  "name": "CircleLoop",
  "description": "CircleLoop",
  "version": "3.9",
  "author": "Mission Labs",
  "browser_action": {
    "default_icon": {
      "16": "16x16.png",
      "24": "48x48.png",
      "32": "128x128.png"
    },
    "default_title": "CircleLoop"
  },
  "icons": {
    "16": "16x16.png",
    "48": "48x48.png",
    "128": "128x128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "script.js"
      ],
      "all_frames": true
    }
  ]
}