We're looking for a couple projects to help us out by providing some feedback on implementing GAuthify: https://www.gauthify.com. GAuthify is a RESTful hosted API service for google authenticator, sms & email multi-factor authentication.
If you're looking to add two-factor authentication to your project please shoot us an email at support@<website>.com with some project information and expected number of users. In return for your help we'll cover your cost of membership.
Thanks!