Yubico Authenticator allows you to use a YubiKey NEO to store OATH credentials (TOTP and HOTP supported, as used by Google, Microsoft, Dropbox, Amazon and many more) used for 2-factor authentication.
Storing the credentials on a YubiKey NEO ensures that your credentials are safe, even if your phone is compromised.
It also makes it easy to move between multiple Android devices.
Market link: com.yubico.yubioath
Web site: https://www.yubico.com
Market downloads: 10,000-50,000
Market rating: 4.4 / 5.0