Yup, there are multiple type "wear in" stands available. Tree Suit, Tree Saddle, Guido's web, Sneaky Sak and others. Some are webbing only, some have a sling type seat, some have a rigid seat or rigid seat, pad and backrest. All things are trade offs. Weight versus comfort is the norm. They're like bows though and are best if you try before you buy.
Common comments are things like:
"PRACTICE AT HOME"
"Not for me"
"Couldn't get the hang of it"
"Feels more secure"
"Couldn't fall out if I tried"
"Buy some knee pads"
"They're just another tool and work great in certain situations."
Like nocams said, use the search feature and read up on them.