Facebook Messenger (Pin Tab)

manifest.json

{
  "name": "Facebook Messenger (Pin Tab)",
  "description": "Switch to Facebook Messenger (Pin Tab) with a single click or a Hot Key (Alt+5)! This add-on also displays the unread count on the add-on icon.",
  "version": "1.0",
  "manifest_version": 2,
  "permissions": [
    "*://*.messenger.com/*",
    "storage",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icons/messenger.png"
  },
  "browser_action": {
    "default_icon": "icons/messenger.png",
    "default_title": "Switch to Facebook Messenger (Pin Tab)"
  },
  "options_ui": {
    "page": "options/options.html"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Alt+5"
      },
      "description": "Switch to Facebook Messenger (Pin Tab)"
    }
  },
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "*://*.messenger.com/*"
      ]
    }
  ]
}