Are they browsers?
I had problems getting it to make a specific one the active one. Things like focus and activate never worked. Using the index also wasn't reliable.
In the end, I had to manually click the page (I just clicked in the top corner at 0,0 - fine for me as there are never any controls up there in my case) in the browser I wanted to force it to become active. Then send it the low level commands (only way I was able to simulate a long keypress in this case) once that browser was active.
But the browsers had different URL, so I was able to identify each one that way. The problem was simply making the right one become focussed ....
