This tool rotates the selected UV polygons about the UV coordinate closest to the pointer. Click anywhere in the Texture view and drag horizontally.
Double-click on UV Points
You can double-click on UV points with the Move, Scale and Rotate tools and the following dialog window will open:
The point on which you clicked (multiple points are also possible) can then be repositioned numerically in UV space.
Active Tool manager options
The same options apply as for the move tool except that the point and edge snapping options have no effect.