Examine source code of Open Emojify

{
  "manifest_version": 2,
  "name": "Emojify",
  "version": "1.0",
  "description": "Emojify is a customizable emoji trail javascript library that follows your mouse cursor, embedding playfulness and personality into any webpage.",
  "icons": {
    "16": "icons/logo.png",
    "32": "icons/logo.png",
    "48": "icons/logo.png",
    "128": "icons/logo.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "emojify.js"
      ]
    }
  ],
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{4f4574f6-4b5b-4c18-950f-d3faddb9cd60}"
    }
  }
}