Designed for horizontal use, which is how I have it.
It annoyed me how the default has a lot of wasted vertical space, and that the combo box would go offscreen/outside the window if you had it as short as it would go. So I fixed that, rearranged some buttons and things, made the minimum sizes shorter. Result seems pretty good, fits nicely next to a chat window if you have a wide monitor.
1.00 - Initial upload.
1.01 - Missed a spot.
1.02 - Added Leave All buttons.