John in Kansas would be the best to tell you but basically if you want to give it a trial and you feel happy with the company then go ahead and download it - regardless of the lack of signature. It says 30 day free trial then its $30 if I read it right. A quick google shows it as being available from a number of reputable places and no obvious warnings!

Your choice of course. If you are on windows there may well be something built in that would do the job.