xFA can add multifactor security to any web service with a few lines of code. We tested xFA on a small network in August 2014. It has cloud-based components to manage multifactor security, along with apps for iOS and Android.

Price: $19.95 per user per year

http://info.authentify.com/authentify-xfa-screencast

Fingerprint authenticators for iPhone 5 and Samsung Galaxy are expected for the near future.