That's awesome. I can see how it would be great for stuff like that!
Hell, even just something like re-arranging a room (especially if you have large, funky or hard-to-move pieces). You might like to see how - or if - a particular idea will work before wearing yourself out, dragging stuff all around.
No, it's not photorealistic and I know there are nicer-looking ways of going about it. But, as I said earlier, you can't beat free and to quickly throw an idea together so easily, I can't imagine too many apps out there fitting that bill.
I've been wanting to rearrange my living room for a while now, but because of doorway, window and cablet outlet restrictions, I'm limited to only a few options. But I'm currently "building my living room" (including the furniture, doorways, window, electrical outlets, etc.) and can easily play around with a few "what if" scenarios at my leisure.
Beats boring old graph paper or "top-view only" approaches all to hell (but I've got those easily available too, with a single click, for any floorplan views I want). Best of both worlds...