Wise Owl Legal fully supports the following Authenticator apps:
Google Authenticator on iOS, Android and Blackberry
Authenticator on Windows Phone
For users without access to these devices, or with particular needs, there are a variety of alternative apps with similar functionality.
However, Wise Owl Legal only provides minimal support for these apps; your mileage may vary.
FreeOTP - an alternative to the official Authenticator apps above (Android only)
WinAuth - For Windows PCs
Web Browser / Firefox plugin / Chrome extension - For any web browser
Java Mobile App - For older devices such as Nokia phones and Palm organisers
Java Desktop App - For Windows PCs, Mac OS X and Linux PCs
Wikipedia may provide links to additional apps