The one in the screenshot/video is dx2 NPC Casting Activity bar
, which isn't working at all for me. It just sits there, unmovable, showing a half-filled bar saying "Ice Comet".
I have Profit running, which turns out to have a built-in target cast bar that is activated by using a macro with /show_window Custom.TargetCasting
Alas, the Profit target cast bar does NOT show up when you press F10, so the only way to reposition it is to go fight something that does long, slow casts, and grab and move the window while it is casting. The window also cannot be resized, which is a booger, I want it bigger. The Drums UI Threat Window
manages to show up when F10 is pressed, even if the default window doesn't, so I dunno why the target cast bar can't.