Phone/tablet usually support touch input with fingers. The term "stylus" usually refers to a pointer device which works with a different method so that the phone/tablet can recognize it as a different type of input than fingers. Stylus usually has pressure sensitive input. There is also a type of "stylus" which is called "capacitive stylus" which has a rubber tips and works in the same ways as finger. In the following when we refer to "stylus" we refer to only the "stylus" in the strict sense, which excludes the "capacitive stylus". Examples of "stylus" for Android platform include Samsung S-pen and for IOS is the Apple Pencil.
MXTNote support stylus in both Android and IOS platform, in writing mode, the pressure input is used to determine the stroke width. If you use a stylus, there is a settings which will only accept stylus input in writing mode, this is useful to avoid accident input by finger or palm. When this setting is enabled, the regular zoom/scroll by finger is available in writing mode, otherwise, in writing mode zoom is disabled and scroll can be done by using two fingers to swipe in the same direction.