Right now, (as of TurboFloat 4.0.7.1: https://wyday.com/limelm/api/#turbofloat ) the only way to track which clients are connected to a TurboFloat Server is to use log files. Specifically, setting the log file notification level to "Notification": https://wyday.com/limelm/help/turbofloat-server/#config-log
In the near future (when we have an exact date we'll update one of these may forum posts) we'll add a library and a simple UI that will allow administrators to view an up-to-the-second list of connected license leases and some abilities (like preventing certain leases from being renewed, etc.).