To create a highlight, tap and hold your finger on a word. Drag the end point to select all the text that you want to highlight. Then tap “Create Highlight” at the top of the screen.
You can change the highlighter color to remind you about exam materials or information that needs more clarification. Just tap on the highlighted text in the book and then in the menu that appears at the top of the page click the circle (it will be the color of the highlighted text).
In the pop up menu that appears select the highlighter you'd like to change to.