Harvestella does not have any co-op or multiplayer options. Instead, it is strictly a single-player experience. That means if you want to share what you're seeing and finding in-game, you'll just have to chat about it with friends and talk to them about everything you've found.
Crossed Wands is a secret unsanctioned student dueling club at Hogwarts Castle. The player can join the club to duel against other students, alone or with a partner, and compete for the title of Hogwarts' top duelist.