I would say it's closer to glue than it is to starch. It makes things VERY stiff! I left it in my project, but the overspray washed off of things and out of my test scraps just fine.
I used it to make fabric roses. If I got my fingers damp, I could reshape the petals and it'd dry stiff again. Neat stuff!
I just got a Scan N Cut and I have heard it works great for cutting fabric with it, but haven't tried it for that purpose yet.