You can feed FR24 via PP using the FR24 feeder software to keep your free Premium subscription. Ignore the PlaneGadget reference.
PP Help:
You can open a TCP/IP server that will output data in the SBS1 30003 format. The port can service up to five simultaneous connections. If you are using the PlaneGadget Radar, enabling this option with the port number set to 30003 will allow third party applications (or other instances of PP) to access the data as if it was from an SBS1. If you are using an SBS1 or an RBv3, which provides data access on port 30003, then you must change the TCP server port in this option to some other port number. Having done that, you could set up other instances of PlanePlotter to access the TCP server and display the data in some other way. You will need to specify the non-standard port number in those other instances of PlanePlotter. If you run multiple instances of PlanePlotter, please make sure that only one of them is set to share data. Otherwise you will overload the server and may lose sharing privileges. You could also allow multiple third party applications to access the data from the receiver via this port.