You ou can find used Wacom tablets for sale on eBay, but you need to do some homwework and research to make sure the year and model of older Wacom Tablet will work on your Mac with Yosemite installled. Download Autodesk SketchBook for Mac MacUpdate 3.8 0.0 Home Graphic Design Illustration Autodesk SketchBook Autodesk SketchBook Version 8.7 Drawing with pro-grade tools and brushes (was SketchBook Express). Generally, the larger the tablet drawing area the more more it feels like you are drawing on paper to the screen as the active drawing area gets closer to the size of your computer's screen, the more freely your hand can move around on the tablet area. I do not know your budget or skills, but Wacom has a wide range of drawing tablet/stylus combinations for every budget There are other drawing/painting/sketching apps in the Mac App Store.that you may find a better fit for you. If you want to draw and sketch more freehand-like, you will need to purchase a drawing/painting/sketching app, as one example Autodesk SketchBook Pro, and you would need to purchase some sort of external USB drawing tablet/stylus combo like these made by Wacom.

Drawing and sketching apps use onscreen tools, so there is no getting around that.

Sketchbook macbook pro