window snap to 3rd

[mahesh]

using xubuntu. If I drag a window to the edge, it snaps to half the screen. This is great as I have an ultra wide. So I get 2 windows like [ ][ ] but I'd really like it to snap to in thirds, like [ ][ ][ ], or even better like [ ][ ][ ], with a terminal in the middle. How can I do this? Is there an app for that?

thanks?