I guess any cage would work, but this one is interesting. Insert naked @gopro #HERO4 camera, adds a cold-shoe mount, tripod mount, shutter button, accepts camera straps, has filter threads (for your NDs and Polarizers, lens cap (protect your naked lens), ergonomic handling, and a cool rangefinder look. @kamerar #Kamerar #GoPro. Hang tight folks, I may be able to get you a coupon code for a discount if you're interested.
Definitely a novelty type item, but functional as well making your GoPro work a bit better as a stills camera. Adds a cold shoe (led light?), shutter button, placement for camera straps, filter threads (polarizers, nd filters), Tripod Mount, and more ergonomic for handheld photos. Can be found at Kamerar.com