Examine source code of :emoji:

{
  "name": ":emoji:",
  "version": "0.1.3",
  "manifest_version": 2,
  "description": "emoji autocomplete anywhere on the internet",
  "homepage_url": "http://emojidots.xyz",
  "background": {
    "scripts": [
      "main/background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_end",
      "all_frames": false,
      "js": [
        "libs/jquery.min.js",
        "libs/jsel.js",
        "libs/bililiteRange.js",
        "libs/jquery.sendkeys.js",
        "main/emoji.js",
        "main/pageCom.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": "icons/icon-48px.png",
    "default_title": ":emoji:",
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "icons/icon-16px.png",
    "48": "icons/icon-48px.png",
    "128": "icons/icon-128px.png"
  },
  "permissions": [
    "https://gist.githubusercontent.com/gonelf/d8ae3ccb7902b501c4a5dd625d4089da/raw/5eeda197ba92f8c8139e846a1225d5640077e06f/emoji_pretty.json",
    "tabs",
    "storage"
  ],
  "applications": {
    "gecko": {
      "id": "gonelf@gmail.com"
    }
  }
}