Examine source code of Jora

{
  "manifest_version": 2,
  "name": "Jora",
  "description": "Make Jira software a bit more useable.",
  "version": "1.0",
  "author": "John Gresty",
  "icons": {
    "48": "48.png",
    "96": "96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.atlassian.net/secure/RapidBoard.jspa*"
      ],
      "js": [
        "board.js"
      ]
    }
  ]
}