Little Bird Swing
I got a demonstration of the swing and a proper view of the thing on North Haven, where Ed Hayes and Bobbie Callahan have one installed for their seven grandchildren. Dubbed the Little Bird Swing due to the decal on the side and the migratory patterns of the lucky kids who use it, the product is still making its way to the mass market. The somewhat confusedly-named National Wood Products of Maine currently manufactures the swing, and in true Mainer spirit, the design, materials and manufacturing are all local. The National Wood Products of Maine website won't let you shop for the swing yet, so the best bet is to give them a call at 207 539-4462.
Update on April 2nd: Campbell just let me know that the most effective way of getting your hands on the swing is to visit this Etsy page.