Examine source code of Squaresie

{
  "manifest_version": 2,
  "name": "Squaresie",
  "version": "1.0.2resigned1",
  "description": "Removes rounded corners from images on Facebook.",
  "icons": {
    "48": "icon.png",
    "96": "icon@2x.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.facebook.com/*"
      ],
      "js": [
        "squaresie.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{a7572126-fe7a-4ead-a002-5cece1317421}"
    }
  }
}