Hi Deo,
I'm not the app developer but last I checked, they were not actively working on the app in terms of bringing in new features etc due to time constraints and other reasons.
So here's my recommendation for an audio Bible. It's the Bible app that I use in addition to Quick Bible. QB is my main for reading, taking notes, highlights, different Bible versions, hymns. This works as a nice app to complement what I can already do with QB.
It has the audio Bible feature for kjv and the Strongs concordance as well.
You can actually adjust the reading speed on it. You have to be online to play the audio Bible. The Strongs is a great tool when doing Bible study. Plus you can adjust the color theme of the app.
Hope you'll find it helpful.