So far we only have the UFO Hunt, which we launched with this forum thread: https://forums.vzfit.com/showthread.php?tid=152
We gave clues out as each UFO was discovered and manually updated stats until the last one was found. Finding all of them is a secret Explorer Achievement on vzfit.com/stats.
We loved putting that one together and are ready to add more! It's in our backlog to generalize that into Explorer Events (to match Play Events) that could give out clues and track everyone's progress automatically.