Fitbit is already supported on Actifit Android version. Support for other wearables is under works.
by @mcfarhat who replied to one of my comments: https://steemit.com/actifit/@riseofth/re-actifit-actifit-launches-signups-and-referrals-and-our-daily-updates-20181228t032826006z
Awesome! Thanks for letting me know!