Last version where it works was 9.0.1 FP9. It is not working from 9.0.1 FP10 - and still not in 10.0.1 FP2. It was simple - hold mouse pointer for a while over tab and it shows which app it is from.
Now there is no indication from which DB is resource opened. For example open script library, form, view - if I open two with same name (for comparison) I am lost. But for lists - there is still hint for forms list, views list.