This applications generates one time passwords based on a secret key and either a counter or the current time. It uses the schemes specified in RFC 4226 and the TOTP draft.
OTPGen is also compatible with Google's 2-step verification. However, don't blame me if it doesn't work and you get locked out. Also make sure to setup the backup options. To set it up follow the following instructions:
Theoretically, OTPGen should work on any phone which supports Java ME with MIDP 1.0. In practice it probably won't ;-) It has been tested on the following devices. Please let me know if it works on something not listed here.
To install the application, enter one of the following URLs in your phone's browser, or if your phone supports QR or DM codes, scan one of the following codes.
ur1.ca/ebecy
http://mene.za.net/otpgen.jad
You can also download the JAR file directly or browse a list of available versions. The source code is available as an archive or Bazaar repository and is licensed under the GNU General Public License.
Feel free to contact me if you have any feedback.