User Guide
A file can be opened from the command line by using the 'wv' command line tool:
wv trace.vcd
It can also be opened by selecting the file menu and clicking 'open'. View settings for an open file are stored in a hidden file called ..traceconfig.
When you open a file, the view will initially be blank.
You can bring up a pane to show available signals by clicking the signal toolbar button ( 
). A pane will be displayed on the left.There are two tabs at the top of the window. The first selects a tree view, which gives a hierarchical view of the design. Each part of the hiearchy can be opened.
If you want to make signals visible, simply drag them to to the view area on the left. Note that you can select multiple items by holding down alt/command and clicking. If you drag a parent node of the hierarchy, all children will be dragged as well.
You can also select the search tab. If you type into the blank, the list will be pared down to show only signals that match some part of the string:
These can be dragged as with the other view.
To remove signals from the view, right click and select the delete item todo: add ability to remove by dragging