Application processes that were invoked by the Application Builder can conveniently be killed if needed.
To kill all such processes, choose
Build > Kill All
or click the 
button.
To kill just one such process choose
Build > Kill Application
or click the dropdown to the right of the 
button. This raises a menu listing the invoked applications that are still running in the chronological order in which they were invoked. Select one item from the menu to kill that process.