I do found a solution, the keyword is overlay with a floating window.
int statusBarHeight = 0;
int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
if (resourceId > 0) statusBarHeight = getResources().getDimensionPixelSize(resourceId);
final WindowManager.LayoutParams parameters = new WindowManager.LayoutParams(
WindowManager.LayoutParams.WRAP_CONTENT,
statusBarHeight,
WindowManager.LayoutParams.TYPE_SYSTEM_ERROR, // Allows the view to be on top of the StatusBar
WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN, // Keeps the button presses from going to the background window and Draws over status bar
PixelFormat.TRANSLUCENT);
parameters.gravity = Gravity.TOP | Gravity.CENTER;
LinearLayout ll = new LinearLayout(this);
ll.setBackgroundColor(Color.TRANSPARENT);
LinearLayout.LayoutParams layoutParameteres = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.MATCH_PARENT);
ll.setLayoutParams(layoutParameteres);
TextView tv = new TextView(this);
ViewGroup.LayoutParams tvParameters = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.MATCH_PARENT);
tv.setLayoutParams(tvParameters);
tv.setTextColor(Color.WHITE);
tv.setGravity(Gravity.CENTER);
tv.setText("123");
ll.addView(tv);
WindowManager windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
windowManager.addView(ll, parameters);