Almost any GUI framework can easily let you know when your own application gains or loses focus (or the other operations you mention). However, listening for these events for other arbitrary applications is definitely platform-specific and may or may not even be possible.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.