Examine source code of GIPHY for Firefox

{
  "name": "GIPHY for Firefox",
  "version": "3.1",
  "description": "Bring the power of a GIF search engine anywhere on the web. Respond to emails, tweets and more with GIFs and Stickers.",
  "manifest_version": 2,
  "browser_action": {
    "default_popup": "index.html",
    "default_title": "GIPHY for Chrome",
    "default_icon": {
      "19": "/img/giphy_icon_19.png",
      "38": "/img/giphy_icon_38.png"
    }
  },
  "icons": {
    "128": "/img/128x128_vertical.png"
  },
  "web_accessible_resources": [
    "/img/*"
  ],
  "permissions": [
    "tabs"
  ]
}