When you use multiple displays, the Online Bible is shown on the primary screen and it seems as if this cannot be changed. 

However, in the Customise Settings menu there is an option to allow the use of the secondary screen. 

In the menu Extra, choose the Customise Settings option.  In these settings you must check the option "Legacy Windows MDI Applicartion Model". Press OK, and you can shift the Online Bible to the secondary screen.