Use APKPure App
Get DaFlasher old version APK for Android
This App is to Flash DaFit Fitness tracker with a Custom Firmware
you can flash any NRF52832 Firmware via your Android Smartphone to DaFit Fitness Tracker.
Here are the Additional Bootloader files:
https://github.com/atc1441/DaFlasherFiles
This Flasher can Flash: Bootloader, SoftDevice and The Application.
This App can also flash the Stock D6 bootloader.