There are several general options which are available on all viewers, which are shown in the toolbar at the top right of the viewer. Some of these can also be accessed through the View menu.
Split View: Provides several options for splitting the view so that multiple views are shown simultaneously for one document. When the view is split, selection of annotations and regions of the sequence are synchronized across the viewers. To close split views click the 
button which is also on the right of the toolbar.
Expand View: Expands the document view panel to fill the main window by hiding the sources panel on the right and the document table above. Clicking this again will return the layout to its original state.
New Window: Opens another view of the current document in a separate window. This allows you to have several documents open at once and gives more space for viewing. This can also be achieved by double clicking in the document table.