Since I started to use the Bible.is app, I used the color coding feature quite heavily i.e. GREEN for anything to do with salvation, YELLOW for promises, BLUE for commandments / instructions on life, ORANGE for anything else.  As a ministry tool, it would be very handy if the bookmarks can be extended to filter items based on color coding to allow quick navigation based on topic / color association. 

(Some more colors to highlight with would also be nice)