Examine source code of FlexIT

{
  "manifest_version": 2,
  "name": "FlexIT",
  "short_name": "FlexIT",
  "version": "1.2",
  "author": "zpottisvold",
  "description": "Flexes it.",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.xledger.net/*"
      ],
      "js": [
        "js/flexIT.js"
      ]
    }
  ]
}