Examine source code of Powertabs

{
  "name": "Powertabs",
  "description": " replacement for the new tab page in Firefox. Provides a searchable and sortable list of all open tabs in the current window.",
  "version": "1.0.5resigned1",
  "manifest_version": 2,
  "permissions": [
    "tabs",
    "topSites"
  ],
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b135354f-55f4-4e57-a6a3-8e9b39457ab3}"
    }
  }
}