Examine source code of mBasicFB

{
  "manifest_version": 2,
  "name": "mBasicFB",
  "version": "1.1",
  "description": "Redirects facebook URLs to mbasic facebook.",
  "icons": {
    "32": "mbasicfb-32.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://m.facebook.com/*",
        "*://www.facebook.com/*",
        "*://www.fb.com/*"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "32": "mbasicfb-32.png"
    },
    "default_title": "Switch to mbasic facebook"
  }
}