Firmware Update on Android

To do the firmware update manually:

1. Download nRF Connect from Google Play Store https://play.google.com/store/apps/details?id=no.nordicsemi.android.mcp&hl=en&gl=US
2. Download the this fw.zip file to your mobile 
3. Open nRF Connect. Tap "Scan" and allow permissions
4. You will see a device named DFUTargXXXX (where XXXX are random numbers. Alternatively you can see SIQB or SIQBB), select "Connect" on that device
5. Tap "DFU" and select "Distribution packet ZIP" from the list, then locate the previously downloaded fw.zip file on your mobile
6. Pick the file from the list and tap "Open". The firmware update process will begin. Wait while the process has completed successfully.

In case you find the instructions hard to follow, please see this video https://www.youtube.com/watch?v=M1zZ51HvYu8. While it is for another product, the steps are the same except you don't need to press any buttons, use zip file from this page and the device name is DFUTargXXXX, SIQB or SIQBB.