Examine source code of Tab Stats

{
  "manifest_version": 2,
  "name": "Tab Stats",
  "version": "0.1.7resigned1",
  "description": "Provide some data about open tabs.",
  "applications": {
    "gecko": {
      "id": "tabstats@glandium.org"
    }
  },
  "browser_action": {
    "browser_style": false,
    "default_area": "tabstrip",
    "default_icon": "tab.svg",
    "default_title": "Tab Stats",
    "theme_icons": [
      {
        "dark": "tab.svg",
        "light": "tab-white.svg",
        "size": 16
      }
    ]
  },
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}