K9 is a companion program to Tardis. If you use Tardis with broadcast NTP then you can use K9 instead. K9 also works with Linux based NTP servers.
K9 has no user interface, none is required because there is no configuration. When you run it you will see NOTHING. It has no visible windows. Do not worry, this is normal. K9 will run in the background listening for NTP time broadcasts and quietly doing its job.
K9 takes less memory than Tardis because it doesn't need all the code to handle user interfaces.