This app was mentioned in 4 comments, with an average of 1.00 upvote
I use SpeedRead with Spritz it works as a google books plugin.There are a few other options here: http://spritzinc.com/get-spritz but not too many sadly.
OK after a bit of digging, for Android users, you can use this app, Speedread with Spritz to addon a spritz text2speech engine that moon+ reader can use. reviews seem favorable with this purpose in mind.
i tried it with my nexus7 (2013) , but couldn't get it to create a spritz account inside the app and couldn't get it to work inside moonreader. i might be doing something wrong though, perhaps my adblockers or permission managers are causing a problem. anyone else want to try it and confirm how useful it is? fair warning, not a free app.
You don't need a persistent connection with the latest version of SpeedRead With Spritz. I haven't tried it yet, but it looks well reviewed.
Ignore this.
You want [this]https://play.google.com/store/apps/details?id=com.randomappcreator.speedreadwithspritzapp)