TOTP generator

Reasonably small (~1 MB statically linked without dependencies, single executable), portable TOTP (Time-based one-time password) generator intended to be used for github 2FA.

TOTP generator for github 2FA

Using with github: copy secret key (named as "setup key" below) and paste it in application settings, optionally (insecure!) enabling saving it to disk (JSON file next to application executable).
Github would ask for OTP/password (6 digits) right away and when logging in next time. Click "Generate OTP now" and copy code or type it manually. Note that each OTP is theoretically valid only for 30 seconds (though service might as well accept older codes to deal with time synchronization and delay introduced by the user). Application shows how much time left for OTP validity in status bar.
Github 2FA TOTP secret

Github: https://github.com/tomek-o/totp-generator.