maximize window option to twitch app.
Don't know if this is implemented on Windows OS, but on Mac OS you can't maximize window to fill the screen (by double clicking the window and there is no option in the window settings on the top panel). There is an option to put it on full screen, but that is not what I'm after here.
Maximizing window gives option to have multiple windows in same screen, without the hassle to use mac's touch pad to change the virtual desktop space to other one. Especially if you use external mouse instead, you really can't do that unless you do some silly keyboard shortcut for it.