I\'m trying to create an always-op-top button/clickable-image which stays on top of all the windows all the time.
The proof of concept is
@Sarwar Erfan's answer does not work any longer as Android does not allow adding view with WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY to window to be touchable anymore not with even WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH.
I found solution to this problem. You can check it out in following question
When adding view to window with WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY, it is not getting touch event