Here's an impressive fan project: An Attack on Titan enthusiast built their own semi-functional three-dimensional maneuver gear. While I wouldn't necessarily take then up to a rooftop to try out, I'm sure they work well enough to be banned by our favorite anime conventions.
Speaking of Attack art, you might have noticed that the latest end card is from Sasha voice actress Yuu Kobayashi
Doujin artist hijituka's interpretation of what you're seeing
Previous end cards
and a bonus goodie...