There are 3 possibilities to transform the selected mesh / FFD point(s) or entire object: you can either...
scale the selection.
The fourth tool works for mesh points only! If you would like to drag the entire texture, please use the tool "Drag Texture" as described below or the settings in the Mesh tab. The UV icon can only be seen in the advanced mode. To activate it, open the "Edit" menu and choose "Advanced Mode".
drags the UV map within selected mesh points.
Before moving points, decide whether you want to work with mesh points, FFD points or an object by switching to the according Edit mode. Then select some points:
- mouse: click on a single point to select it, hold down the [Ctrl] key additionally to multi-select points or drag a selection box
- keyboard: click the Up/Down/Left/Right key to select a single point and hold down the [Ctrl] key additionally to multi-select points
Now, there are 3 different ways of applying a transformation change:
- keyboard: you can move the selection with the shortcut [Shift + Up/Down/Left/Right arrow key]
- dialog: make a right-click on the move/rotate/scale icon to open the "Relative ... Dialog". There you can enter a specific numeric value and apply the change. Please note, that this works in a relative way, not absolutely! You can either undo the changes done in the dialog by hitting the Undo icon or by applying the inverse value, e.g after scaling by 50%, you may scale by 200%.
- mouse: you can move, rotate or scale the selection by holding the right mouse button pressed and moving the mouse up, down, left and right. You can switch from one transformation mode to another by clicking the respective button or by using the keyboard shortcuts. Press the following numeric characters on your main keyboard:  for moving,  for rotating and  for scaling. (When the Toolbox is active/selected, these shortcuts will not work. In that case, click into the Warper's main interface to deselect the Toolbox). If you would like to transform along a certain axis, you may lock it with the according buttons X, Y, Z.
Please change to the Mask tab before using the following tools. This will show you a white texture instead of the texture chosen before.
The chapter covering the ScreenMask explains as well how to work with the mask in more detail.
Use these buttons (or the according shortcuts) to change between editing the object, the FFD or the Mesh. (When the Toolbox is active/selected, these shortcuts will not work. In that case, click into the Warper's main interface to unselect the Toolbox)
Objects can be selected and edited. (Keyboard Shortcut [O])
FFD control points can be selected and edited (Keyboard Shortcut [F])
Mesh control points can be selected and edited (Keyboard Shortcut [E])