Here is a simple Windows console application TOTP authenticator, which will generate 6-digit authentication codes that you can use on sites which use multi-factor authentication.
I wrote it mainly for use with GitHub's 2FA (2-factor authentication). My main reason was that I wanted to avoid giving GitHub my phone number, installing apps on my phone, or relying on a third party authenticator.
This authenticator relies solely on standard .Net classes.
Downloads
executable - (Windows console application) use this to generate your own 6-digit authentication codes. Put your secret in a file called
secret.txt in the same directory as the executable
source - the source code package, available as a Visual Studio solution