I was also definitely surprised this didn't already exist; but hey I never thought of it either! My apartment has a bunch of bookshelves with hanging bars in th

I was also definitely surprised this didn't already exist; but hey I never thought of it either! My apartment has a bunch of bookshelves with hanging bars in them (?) definitely not big enough for normal hangers unless you turn them sideways and lose a bunch of space. On this design though, my biggest criticism would be that it requires the hanger to be leaning against the wall when folded, to not fall at an angle. While that's fine for the co-designed rack she has, it makes them a lot less useful on their own or in other randomly wall-to-rack spaced closets (even says so in the kickstarter). The simple solution is to move the hook to be centered over the folded hanger, so it's balanced when folded. It'd look super goofy and not hang right unfolded, but that's probably fine. Surprised none of the prototypes tried that.