Google Analytics is used for tracking user interactions. The following events are reported:
1. installation
2. default selected voice name
3. user changes settings
4. user starts reading (including event source, e.g. hovered text, browser selection, space key)
5. user interrupts reading (including event source)
6. user navigates with the arrow keys (if enabled in settings)
7. speech error
8. user clicks any URL in the options page (no-voice information, reviews, support)

Analytics can be disabled in the General page of Options.