C'mon don't just close issues, I'm also wondering if this is something that might get into this great application.
@peteruithoven, I closed this issue because I don't feel this is a feature Spectacle should have.
First and foremost, I'm a big fan of Spectacle and am very appreciative of it. Thanks, @eczarny!
I searched for this feature and stumbled on this thread. I second @vancetran and would greatly appreciate replicating the Windows Aero functionality. I'm curious as to why you think this is a feature that you don't feel that Spectacle should have, @eczarny. I'm of the opinion that others would greatly enjoy this functionality and that you'd see many more folk using Spectacle as well.
@isaiahjoo You can replicate the Windows Aero Snap feature with iSnap, free on the Mac App Store. https://itunes.apple.com/us/app/isnap/id420332190?mt=12 . I hear that Cinch and Moom are also great options.
Many thanks to @eczarny for creating this software. I initially didn't like that Spectacle didn't have drag-to-snap, but now I actually prefer using keyboard shortcuts exclusively to snap windows. I find it to be faster and offers greater control. My favorite feature of your latest release is being able to snap windows to 1/3 and 2/3! Keep it up and I encourage everyone to head over to http://spectacleapp.com/ and donate if you use the app every day like me.
It's unfortunate @eczarny won't consider user feedback or explain his/her position on this. But then again - spectacle is free, so you can have your money back :)
For me personally, dragging with the mouse is critical. There are some other fantastic programs that do that.
It's worth noting that macOS has built-in support for side-by-side window arrangement. It's REALLY strange. You need to press and hold down the green "maximize" circle in the title bar to enter side-by-side placement mode as explained here.