Examine source code of Slackmoji

{
  "description": "Browse, search and add emojis to Slack with one click",
  "manifest_version": 2,
  "name": "Slackmoji",
  "version": "1.1.1resigned1",
  "homepage_url": "https://slackmoji.com",
  "icons": {
    "48": "icons/icon-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.slack.com/customize/emoji*"
      ],
      "js": [
        "jquery.js",
        "slackmoji.js"
      ],
      "css": [
        "style.css"
      ]
    }
  ],
  "applications": {
    "gecko": {
      "id": "slackmoji@mozilla.org",
      "strict_min_version": "45.0"
    }
  }
}