Rover Instruments updated their website this week. The old one has been replaced by a completely new one!
You probably tried to access their site exactly during maintenance.
It is up and running again.
In order to edit/upload channel lists (called "plan"), you need the SMART PRO version: you download the SMART software and then buy the license activation for the PRO version. If you install SMART for the first time, you will be allowed to use the PRO version for a limited amount of time. Use this trial period to update and edit the transponder lists (you can download ready made ones from Rover Instruments, as well).
Congratulations for the great purchase. It is not frequent to be able to get a professional Rover Instruments meter "at a ridiculously small price".
Beware that your's is working: some months ago there was one on sale, which had problems with the tuner. You should test your meter by checking known frequencies and, if possible, compare the measured values against a reference (calibrated) meter.
Regards,
vma