Notifications when screen is turned off

Thanks but not for the Lock Screen, just when the phone is off, the smart pop up view allows it to be a floating icon, like gmail, that floats on all screens. I'm asking about when screen is off & I gat a whistle notification that I have just received an email or text, I use to get a white icon from either gmail or message in the center of the screen that would stay there until I woke the screen up so if you did not hear the whistle you can see that you just got an email or text with out waking up the screen. I was able to get the floating pop up once on the off screen but it doesn't stay for long which is no good if you are not looking at the phone when it happens.