Main problem: No menu. Where are the settings? The first thing I wanted to do was move the file treeview to the left side; I don't know what country the authors live in, but in Western countries we read from left to right. But nope, there's no View menu or anything of the sort.
Then I examined every other little button around the UI, to no avail. I want to get stuff done; not play with an Advent calendar, hunting for goodies.
