This app is really long in the tooth, it could do with an update where everything is displayed using the material native UI. But for now, I have just done a quick update to get it to the Google Play new standard. The app bar was using some old libraries that I had to run a bunch of function override’s to get it to work on the settings screens, and also it has lost the menu icon on the top left. But I don’t think the menu was that useful. You can still side swipe to access it.
I found a bug when you rest to the default language. This has also been fixed
The new update is live on the Google Play and this site. It is currently pending on Amazon.