Could be better. :(

Works as advertised, but does not write all the data to Fitbit. Specifically does not write calorie data. Bit misleading because it shows that it can read this data from HealthKit but does not show what it is possible to write to Fitbit.

Worth the money if you just want to get your basic data out of your Fitbit account into HealthKit.

FantasticNatSimplyAmazing about Data Manager for Fitbit