sort of - https://activity.club
your friends on fitbit will have to join this app to compete with you. but (obviously biased) its way more fun!
we have a watch app in beta too, if you want to help test. but the non-beta version is in app store, and it reads the steps that your watch records.
cheers
Will team vs team feature be coming? That's something we've been talking about for awhile as well.
Is their an app yet that allows you to compete with fit bit users?
Sync Solver App (already available and I use it) will sync your Apple Watch -> Health -> Fitbit App