Firebug like tool for WPF?

I'd like to run my program and hover on elements and have a program show me in the visual tr开发者_StackOverflowee what I am hovering. I tried 'Snoop' but it just shows me a visual tree without the ability of actually hovering on the elements at runtime. Do you guys know of such a tool?

you can do it with Snoop - hover elements at runtime, just click ctrl+shift while hovering with the mouse.