Moderately suitable for clicking, halfway useful as Crayon

This pen looks almost like a mechanical pencil with additional screw - were it not for the small plastic disc on top.
The disadvantage of this disk is that is sometimes difficult to control at which point of the display set it up first. You have to overcome a little to press firmly enough - the display is not scratched. The pen is therefore not much help when you click on the screen; as rather unreliable when dragging objects, since they easily let go accidentally.
Of course that's not the main destination of the pin. I tried in a drawing program to make handwritten notes - they have become illegible. The writing feel is unusual, what is like improve experience after a few weeks - at the moment I've just with small, round shapes difficulties in enforcing the right spot pressure.
If there is more attention to keep the pen vertically, it may be of some help in drawing lines etc. However, it remains the case that a serious graphics editing via smartphone is not possible - any more than with your finger.
The pin can be at the shell of the tablets or smartphones fix, but only if it is very thin.