Boox Color Series User Manual page 62

Scribble
The Scribble toolbar is floating on the screen. You can long press on it and
drag it around on the screen.
Scribble is enabled by default. You can enable / disable it by tapping the
Scribble icon located on the upper part of the screen.
You need to pop up the Scribble toolbar by tapping the Scribble icon
located on the right bottom of the screen. Or you can also enable it from
the Floating Toolbar.
Eraser
Pen Brush
Zoom
Color
Undo and Redo
Save
Hide the Menu
Export