spen pointer /s mouse

well there was spen pointer function in one off the leaked videos 

https://youtu.be/SRJSZz7oWf8 here is the video 

we can use the spen to move cursor on the screen and interact with it and also there was app called smouse on play store that also make same thing but it not work anymore are we can get back this feature using the phone with spen from air use it as mouse will be awesome

https://play.google.com/store/apps/details?id=io.kinesthetic.smouse