Examine source code of Inbox Theme for Gmail

{
  "name": "Inbox Theme for Gmail",
  "description": "Brings the Google Inbox experience to Gmail",
  "homepage_url": "http://flowapps.co/inboxtheme",
  "author": "Flowapps",
  "version": "1.1.5resigned1",
  "icons": {
    "16": "img/icon-256.png",
    "19": "img/icon-256.png",
    "38": "img/icon-256.png",
    "48": "img/icon-256.png",
    "128": "img/icon-256.png",
    "256": "img/icon-256.png",
    "512": "img/icon-512.png"
  },
  "manifest_version": 2,
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*"
      ],
      "js": [
        "in-min.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{db15e6e3-7234-4bd2-9d1f-e4d7fad4208d}"
    }
  }
}