a.placebetween.us - Find a meeting point based on place type
BubbleGlobe - Book unique things to do with locals
Zenly - Zenly is a GPS tracker to locate your friends in realtime.
Everfest - A global calendar and search engine for festivals
Works For All - Find a central meeting place for everyone in the group
Traveller Stash - Curated directory of 60 resources & tools 4 modern traveller