Google Play Books just keeps getting better with every update. Despite it having the ability to read out loud to you for a while, the app was updated with an option for higher quality voice. You have to be connected to the internet to use the high quality voice, but it should be a lot more pleasant to listen to than before.
Google has also added pinch to zoom and double tap to zoom for all books, along with text editing features for notes and recommendations in your library and at the end of every single book. To grab the update, open the Play Store on your device or hit the source link. It’s free, as always.