Finally Verizon upgraded the Nokia Icon OS

In the last couple of days Nokia has upgraded the Nokia ICON OS from Windows Phone 8.0 to Windows Phone 8.1. They took a very long time to do this. Anyway it is better late than never.
Now the Health and Fitness app can record your footsteps as Machine Data has appeared in your Settings list.

Read more about Sensor core here:
http://stackoverflow.com/questions/26558729/why-do-i-get-this-sensornatavailable-error-what-is-wrong/28547660?iemail=1&noredirect=1#28547660

I was using the Windows Phone 8.1 developers preview and this also got upgraded.
The apps created using Windows Phone 8.1 Developer's preview cannot be opened in Windows Phone 8.1

I also notice differences in the way the apps react to OS. At least in the case of Health and fitness apps I notice two things (I will confirm in a future post with proof).

1. The GPS tracing via map in the app appears to have more resolution.
2.  More imporatantly the distances measured are quite different for the two OS Versions.

The OS 8.1 versions seems to measure a greater value for the measured distance than that measured on a OS 8.0 phone for the same track.

I invite anyone who reads this to comment.