Sound support is provided by google text-to-speech engine https://play.google.com/store/apps/details?id=com.google.android.tts . You should have it installed and english language downloaded.
We have made a kidreadler interface simple, two zones on bottom are moving words forward and backward. Right middle zone is switching syllables if word is long/complex. Nothing more needed.
Get more texts
If you are looking for additiona texts to be added to application you have just to download them with your cell phone or tablet and application will read all from Downloads directory.
The texts will be stored on http://kidreadler.com/download-more/ page.