Suzie, I have only used MultiPSK. It's totally free, and decodes just about every kind of decodable signal out there, including RTTY.
Sometimes it's hard to find a strong, copyable signal that actually
is RTTY, so that part takes some patience (as in, is my audio setup correct? Is the audio level into the soundcard OK? Is the software set up right? All of this could be good, and then...am I getting a good signal? The patience is sifting through these variables. But once you "get it right", then everything after that is usually good to go.)
See this thread (my post is #6) about how I used MultiPSK to decode marine weather FAXes.
http://www.radioreference.com/forums...x-signals.html