How can I manage which of two displays is used to open an application?

Since adding a second display to my Mac Pro (early 2008) running OS X 10.10.3, I have not been able to control which display is used when an application is opened. Sometimes an app opens on the display last used. Other apps, for instance, QuickBooks 2014 for Mac, always open on the same display, regardless of the display used last.

Can anyone point to a discussion of how OS X determines which display will be used? And, can I select the display to be used? If so, where does this occur?

I've examined Display Preferences without finding a solution for these questions.

Thank you,

Doug Johnson