The current UI to select which collection is viewed is cumbersome, requiring at least 3 taps in a somewhat difficult to comprehend dialogue box. Perhaps many that want to have access to 2 languages or 2 Scripts of the same language, would prefer to simply swap screens (like alt-tab in windows) to see the other language or script. Also since most users are looking at phones, they are more likely to want to only display one language/collection since their screen is so small.
To accommodate these factors, could the function of the current button in the upper right corner be changed so that tapping it changes to the next book collection. Tapping again would change it back to the former book collection.
Users wanting to display 2 panes or verse layout could still select this layout through the menu, Language & Layout. If there is a way for android to recognize a “long finger press”, then holding your finger on the upper right screen button could also bring up the Language & Layout menu.
The ability to display more than one language is a powerful feature. I hope making it more accessible can be done.