is compatible with the following or newer devices:
Samsung Galaxy S5 / Galaxy S5 mini / Galaxy Grand 2 / Galaxy Note 3 / Galaxy Note 3 Neo / Galaxy Note 2 / Galaxy S4 / Galaxy S3 / Galaxy S4 Zoom / Galaxy S4 Active / Galaxy S4 mini / Galaxy Mega 6.3 / Galaxy Mega 5.8 / Galaxy Note 10.1 (2014 Edition) / Galaxy NotePRO (12.2) / Galaxy TabPRO (12.2/10.1/8.4).

Gear fit is controlled with an Android app. this is also available or installable on the Samsung s6 edge. So I see no reason why it shouldn't work.