This app was mentioned in 3 comments, with an average of 1.00 upvote
Yep, something like this lets it work with any Android phone https://play.google.com/store/apps/details?id=com.solderbyte.openfit, which is nice. Was there an app store for it? I know it runs a custom OS so I'm guessing not. Sorry that yours broke man, that's gotta suck :/
To get functionality of the device use this.
https://play.google.com/store/apps/details?id=com.solderbyte.openfit
File transfer you will have to plug it into your pc and move them around.
FYI i have made an app for the Gear Fit, since samsung support isnt the best.
https://play.google.com/store/apps/details?id=com.solderbyte.openfit