download those files
then install gear fit update 1.25.apk
open the app and pair the fit. it should connect. you can use it like this but the update ads a few features like screen rotation.
now you need to get a samsung phone that is compatible and update the fit to 1.49
now you uninstall GR.gearmanagerstub.apk and gear fit update 1.25.apk
now install gearfitmanager1.49update.apk and gearfitinstaller.apk and pair your device. everything should be working perfectly.
i am also claiming the first nexus 5 working with the gear fit :P
Edit: I just found a "lite" version of s-health that DOES work. Here's the link
Apparently I can post links now too. Awesome