Pressing the addon icon in the extension bar will read aloud everything on the page, unless you have some text selected, in that case it will only read what is selected. Pressing the arrow icons on the extension will advance or back track one paragraph worth of reading material.

The extension also employs editable shortcut combinations which can be triggered in Chrome or Globally.

For a free product, the voice options are quite good with a number of premium options from Google and Amazon.