Edit:
Official Lemmy Community:
https://lemmy.world/c/syncforlemmy
This should open the community in your instance
Looks like the Boost for Reddit Dev just reserved a Lemmy Community…No official announcement yet.
Proof: https://old.reddit.com/r/BoostForReddit/comments/14ehiqs/_/jouvuok/
Direct Link to the Community: https://lemmy.world/c/boostforlemmy
Same with Infinity for Android, though I did use Sync on iOS.