Apple Pencil or Surface Pen

Procreate

Only available on iOS but a really great program. Has all the functions one needs including full screen mode, layers, color picker, custom palettes, selection tool and gallery. Tilt sensitivity with the pencil tool is excellent. Single one time fee to purchase. If you are using a ipad this is probably the way to go.

Sketchbook

Available on both iOS and windows. Has all the functions you need including full screen mode, layers, color picker, custom palettes, selection tool and gallery. Tilt sensitivity with pencil tool is excellent. One problem is that the app will not let you work off line in iOS. I think the limit of not being able to work off line is unreasonable and would not recommend this app on iOS as a result. Many times the figure studio I am working at may not have a WiFi connection and sometimes it is nice to work on the plane or plein air for instance. However the windows 10 version seems to work fine off line so I would recommend this app if you are working in windows.

Adobe Sketch

Tilt sensitivity

Sketchable

Available on windows only. Has many of the features you want but also lacks some. Very limited tool array and no selection tool. No tilt sensitivity despite what thier website says. I down loaded both the crispy and edgy pencils from thier site and neither really is tilt sensitive for me on my system. I posted a question on thier website about this and have not heard back yet. If I can get the tilt working with thier app I will update this post. In contrast the sketchpad pencil from windows ink has great tilt and pressure sensitivity so I know it is not my surface pen, surface book or windows that is causing the problem so it must be their app.