Launch app with UI in background Is it possible to start a regular app – with a GUI – in the background, without displaying its UI? Also, it needs to be launched from the shell terminal, not from java.

What I'm using currently:

am start -n com.nolanlawson.android.simpletalker/.MainActivity -e text "Sample text for TTS."
I don't believe you can, however you could try using the StandOut library to achieve your goal. The StandOut library allows you to have floating windows on the screen. 
StandOut Library: https://github.com/pingpongboss/StandOut