[ProblemFactory]

> Someone mentioned the uncertainty of relying on a Google service, considering Google's recent "spring cleaning" of Google Reader.

Google Authenticator is not a service that Google can even shut down. It's an open-source implementation of open standard protocols.

You install a library + few tens lines of code on your server, and users install the app on their phone. After this, no Google server or service is ever touched in the authentication process.

Even if Google decides to pull the app from the store, it's open source: you can build it from source and put a copy up yourself.

[Create]

Current Version of the Android app is now proprietary and it isn't clear whether the source code repository will be getting any more updates.