The Freewin plugin lets you open a free-standing view of the body of a selected node. This view also contains a basic text editor. The window remains locked to the host node even if the host gets moved to a different position. If you edit the body text in the host (that is, in the main Leo window), the changes get echoed to the Freewin window. It you edit the text in the Freewin window, the body of the host node picks up the changes. CTRL-s in the Freewin window saves the host node's body.
The original idea for Freewin was to get a convenient way to view and compare two or more nodes, and to be able to edit them while comparing. This can be done by adding body editors to Leo's window, but if you have tried it you know that this method is very error-prone and confusing. This is because none of the body editors is locked to a specific node. So if you select a different node in the tree, the active body editor changes to that node. It's hard to tell which body editor is active, and if you are like me you are always typing into the wrong node. Also, if you want more than two body editors, Leo's window will start getting cluttered. You could use the splitter menu to open a free-floating body editor, but the error-prone operation remains.
Freewin works well for its original goals. It turns out that it can be also used for note-taking in a different virtual desktop. Here's the situation: I want to take notes on a series of calculations I'm making in another (non-Leo) program. I have created a node in a Leo outline for these notes. But I don't want to operate the other program in the same desktop as Leo, because they are both large and overlap each other a lot, and also because I may want to select different Leo node while still being able to take my notes.
My solution is to run the other program in a different virtual desktop. I open Freewin on the note's node, and then move the Freewin window to that other desktop. Now I can take notes while working with the other program, and even if I move around or change outlines within Leo, my Freewin window remains connected to the notes node.
It's very convenient. I've attached a screen shot to illustrate.
The minibuffer command to open a new Freewin window is z-open-freewin. You can open as many as you like on different nodes.