Kindle Tip: Aa menu

Did you know that the Aa option in the kindle book menu does more than just change text size?

This button is also the menu for:

font type,
line spacing,
margin width.
Page color (on the Fire)
and on some kindles it manages Text to Speech.

Some books are not set up to do a few features. Example, the publisher may have set the font type and not allow it to be changed (a pet peeve that has left me unable to read some books).