Examine source code of Get Emoji

{
  "manifest_version": 2,
  "name": "Emoji",
  "description": "Collection of more than 1000 emojis. Just select, copy and paste.",
  "icons": {
    "48": "icons/48.png",
    "96": "icons/96.png"
  },
  "version": "1.0",
  "browser_action": {
    "default_popup": "index.html"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d85addec-0494-4198-888c-5b073c36a24c}"
    }
  }
}