http://www.curseforge.com/projects/curs ... 4-windows/
I downloaded it yesterday night, seems to work very well. It's in beta so usual caveats apply.
The big feature (which I haven't tried yet), is the ability to sync addons between two or more computers, which is why I downloaded it. I have to sync between my desktop and laptop and I was doing it via some horrible USB-stick shenanigans every few weeks.
The app uses .NET framework, seemed to have fewer ads and a better interface than the old v3 client. So far so good...
Oh, I think it is supported on Mac also now.