I've always used BetterSnapTool from the same developer, which is basically the window management features of BetterTouchTool as a standalone app. Not sure why

I've always used BetterSnapTool from the same developer, which is basically the window management features of BetterTouchTool as a standalone app. Not sure why it's not free, when BetterTouchTool is, but I'm not going to begrudge him that one-off payment for something I use every day.