Windows 10 Mobile might feature call recording. The latest Windows 10 Mobile build number 10149 contains hints about the heavily demanded feature.So far, Microsoft has not been able to bake the functionality inside the Windows Phone platform. Not even Apple has added it in iOS, or Google in Android.
When Voice recorder app is launched in Windows 10 Mobile 10149 Build, it creates a folder named as “Recorded Call”. It can be spotted when you open the file explorer where other folders like Document, Music, Pictures, etc are listed. We did check on the file explorer before launching, and the folder wasn’t there. This clearly means, the app creates it and has permission to use it.
Source WindowsCentral