FreeOTP is now available for Android and can be installed from Google Play.
FreeOTP, which is based on open standards, is a “multi-factor authentication client based on the HOTP and TOTP standards.”
The OTP in its name stands for One-Time Password and HOTP is HMAC-based One-Time Password (algorithm). TOTP – Time-based One-time Password (algorithm) – is an extension of HOTP.
Aside for support for HOTP and TOTP, FreeOTP also features support for native QR code scanning. The iOS version should be available in the is Apple App Store soon.