Quest Master is a new game by Skydevilpalm and Julian Creutz looks like a Zelda Maker where you can design your own dungeons and then share them. Hopefully their sharing ability is a little more robust than what Nintendo did with Mario Maker. No release date yet, but apparently a demo is coming soon.
Sounds very similar to Super Dungeon Maker, although I haven’t tried that one. However I love Mario Maker and user generated content, so I’ll keep this on my radar as well!