In the app, you just tap the screen when you are in one of the chapters. It will bring up the settings type menu from the bottom. Right below your progress bar there are 3 buttons. The farthest one to the right, next to the dark mode, turns the BulleTags on/off. On a device not in the app it's similar. Tap the screen while in a chapter. In the bottom right hand corner a little button will come up to turn them on/off.