Examine source code of Passphrase Generator

{
  "manifest_version": 2,
  "name": "Passphrase Generator",
  "version": "2.3",
  "description": "Passphrase Generator",
  "icons": {
    "32": "icons/passphrase32.png",
    "48": "icons/passphrase.png"
  },
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_icon": "icons/passphrase.png",
    "default_title": "Passphrase Generator",
    "default_popup": "popup/passphraseGen.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "passphrasegen@dblv.com"
    }
  }
}