Freeciv

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "Freeciv",
  "description": "Freeciv is a strategy game playable in a browser using HTML5.",
  "version": "2.6",
  "manifest_version": 2,
  "icons": {
    "128": "freeciv-web.png"
  },
  "app": {
    "urls": [
      "http://play.freeciv.org/"
    ],
    "launch": {
      "web_url": "http://play.freeciv.org/"
    }
  }
}