I'm running El Capitan 10.11.4 on a 2014 Mac Mini.
I'm often running 10-14 apps at one time as I work writing reports, word/excel/Adobe/Safari/iTunes/calendar/etc...
Frequently I want to open another app, I want it to open in the background and go back to word/excel and keep working, but the launching app takes away my focus, sometimes 2 or 3 times. once for the splash screen, once for the open dialogue window, and again after I click 'new document'.
Another situation, I update an app in the background, like 1Password (beta) and every step it takes my focus back to the app being updated.
Is there anything I can do with Unix/Terminal, etc. to force all app activity to be done in the background, or to keep OS to respect my focus?