There is a guy near Houston that makes a rest that will hang in a blind window. My wife carries her's from blind to blind. I'll see if I can find a picture.
This the one you talking about? I first used one in 2006 and really like them. We had one in every deer blind and especially for first time hunters of any age, they worked great. Very simple design and were made by are retired LEO from Katy IIRC.