I upgraded my Mac's OS from macOS Sierra to macOS High Sierra today and found one feature disappeared: I used to swipe up on top empty area of a window to maximize the window to "fill" the full screen (not the natural full screen, ie, a new desktop space, just making the window as large as possible in the same space); also, by swiping down when the mouse position is on the window top I could resize the window to default size, in the center of the screen.
I can't remember if it is a feature enabled by a util app (like Hyperdock) or can be configured in System Preferences
. I googled around but cannot find it.