Not all Dashboard widgets will be compatible with that app though; only ones that are pure javascript and html (widgets can also have Objective-C plugins, which will be compiled for OS X not iPhone OS).
I really don't care for it. The idea that you have to close down your other app to open another app to use the tools doesn't make an sense to me.
For example when I need a calculator is usually if I'm looking at something on the net such as a bill. I'd have to close that down to get to my calculator. Or I might want to look at the weather while I'm planning my weekend trip again, I'd have to close down the app to get to my weather.
Many (most?) Dashboard widgets are regular Javascript and HTML. All this guy is doing is putting little draggable Web views on the screen. Nothing is being emulated.
As I said in my earlier post, some widgets do have native Mac code plugins that they use as well, and those simply won't work on the iPad.