We have developed app that is help you when you need authentication code. Authenticator generates 2-Step Verification codes on your phone. In addition to your password, you’ll also need a code generated by the Authenticator app on your phone.

Features:
* Generate verification codes without a data connection/offline usage
* Authenticator app works with many providers & accounts & sites
* Simple setup via QR code
* Full support for time-based and counter based one-time password.

this app developed from open source : (https://github.com/emre-g07/GoogleOTP)