Examine source code of Craigslist Link Activator

{
  "manifest_version": 2,
  "name": "Enable Craigslist Links",
  "description": "This extension converts the text URLs in any Craigslist Ad to clickable links. So, no more copy-paste.",
  "version": "2.1resigned1",
  "browser_action": {
    "default_icon": "icons/button.png"
  },
  "icons": {
    "16": "icons/button.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "homepage_url": "http://tapclassifieds.com/",
  "permissions": [
    "activeTab",
    "tabs",
    "http://*/*",
    "https://*/*",
    "contextMenus",
    "webNavigation"
  ],
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "linkEnableUtil.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "extension.cl-link-activator@tapclassifieds.com"
    }
  }
}