how to make virtual joystick follow your finger when dragging on screen

Hello guys
maybe you know ,how to make virtual joystick follow your finger when dragging on screen, as now only the thumb part is moving, but the whole joistick is still in the same location where was the first touch of the screen.
I have added few screenshot , marked with A is how it works right now as defalut. Marked with B is the result I want to get, is it posible? as most of the games on android have this, and for players its a bit of frustration, when controler is not folowing. :confused:
by numbers I marked the finger location 1 is first touchn. 2 where its draged to.