Windows 10

This does pretty much exactly what it should, and I like that it's just a set-and-forget, one-time-run thing. I don't know if this is just Steam, but Steam specifically is still pretty pervasive about yanking all focus away from whatever I'm doing multiple times in a row.

I tested by slowly dragging a window around on my second screen while Steam opened up on my first. Sure enough, three times my cursor just slipped off as the window came to a grinding halt and forced me to start the click-and-drag again, just to kick me off again until Steam was satisfied its presence was thoroughly announced.

I know this whole thing sounds like such a petty gripe, but words can't describe how absolutely aggravating this is when it happens regularly. If I ever worked with someone who behaved like this, I'd be going hands-on in no time and making sure they never come within eye-sight of me again.