Examine source code of onepgr screen sharing

{
  "name": "OnePgr Screen Sharing",
  "author": "OnePgr, Inc.",
  "version": "3.1resigned1",
  "manifest_version": 2,
  "minimum_chrome_version": "34",
  "description": "This Chrome extension is developed for http://onepgr.com/. It doesn't do anything except capture content of your screen.",
  "homepage_url": "https://app.onepgr.com",
  "background": {
    "scripts": [
      "background-script.js"
    ],
    "persistent": true
  },
  "externally_connectable": {
    "matches": [
      "https://pgr.pagekite.me/*",
      "https://app.onepgr.com/*",
      "https://staging.onepgr.com/*",
      "https://onepgr.com/",
      "https://*.google.com/"
    ]
  },
  "icons": {
    "16": "logo16.png",
    "48": "logo48.png",
    "128": "logo128.png"
  },
  "permissions": [
    "desktopCapture"
  ],
  "web_accessible_resources": [
    "icon.png"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "admin@onepgr.com"
    }
  }
}