How can I launch apps on the screen that the mouse cursor is on?

I had wanted to do this myself. Here is what I found:

1. Go to the CompizConfig Settings Manager (type compiz into the Dash).
2. Click on the Place Windows item in the Window Management section.
3. Select Use output device with pointer from the Multi Output Mode dropdown menu
4. Make sure you also click the checkbox that enables the Place Windows "plug-in"

You may run into trouble with the behavior remaining unchanged unchanged in certain cases. This happened to me, but then I realized the reason: Smart output mode will place a full-screen application on a monitor with a higher resolution by default, even if the "Use output device with pointer" option is selected. To fix this problem, I changed the Placement Mode to Pointer. I also found that the other available options, like Centered, also achieve the result of the window being placed on the screen currently containing the mouse cursor. I recommend trying out each of the options to see which one you personally prefer (personally, I found that I like Centered the best). It seems that Smart mode is trying to be "too smart" for what I want, I believe that it assumes that one wants bigger windows to be placed on the higher resolution screen regardless of what other options are selected, which is not necessarily what one may want in many cases.

I hope this helps!