Windows Phone 8.1 – backward compatibility

According to Microsoft assurances applications that have been provided for Windows Phone 8.0 should also work with phones updated to Windows Phone 8.1. In most cases it is true. But sometimes small changes in OS can cause that application will not work as we expected. In my case issues occurred in SpeedDial / SpeedDial Pro apps. The Windows Phone’s SDK didn’t change in that area and both applications source code compiled correctly without any errors. Unfortunate Microsoft has changed behaviour of OS. In this case issues were generated because PhoneCallTask is working a bit differently than in Windows Phone 8.1. [...]