Writing

The page, the slash menu, formatting, comments, footnotes and the right-click menu.

The page

Select a document in the binder and type. The usual Markdown shortcuts work as you go: # and a space starts a heading, > a quote, - a bullet list and 1. a numbered one. A scene break is Cmd Enter.

The pill at the bottom counts the words in the document. Give the manuscript a target in Settings > Project and it shows how far along you are.

The slash menu

Type / on an empty line for everything a document can hold. Keep typing to narrow the list, then press Enter.

Text, Heading 1 to 3, Quote, Bullet list, Numbered list and Task list.
Code block and Table.
Image picks a picture to put on the page. You can also drop or paste an image file straight onto the page. Images are kept in the project folder, beside the document.
Scene break and Footnote.
Note is a note to yourself in the middle of the text. It stays in the file and is left out of Word, EPUB, PDF and Markdown exports.
Properties adds a block of fields at the top of the document, the front matter other Markdown tools understand.

Formatting

Select some text and a small toolbar appears above it.

Heading steps through the three heading sizes and back to text. The research note button turns the selection into a character or place, or adds it as another name for one; see Characters and places. The keys for all of these are under Keyboard shortcuts.

Comments

Select a phrase and press Cmd Shift M, or the comment button, then type and press Enter. With nothing selected, the comment is left at the cursor instead.

A commented phrase on the page and the same comment listed in the inspector

Every comment in the document is listed in the inspector under Comments. Click one to jump to its text; Edit and Delete sit beside it, and right-click offers Go to text too. Comments are kept in the document's file and never appear in a Word, EPUB, PDF or Markdown export.

Footnotes

Cmd Shift F, or Footnote in the slash menu, adds a footnote at the cursor. They number themselves, and they go out with every export.

Find

Cmd F finds within the document you are in; press Replace in the find bar to replace as well. To search every document in the project, use Cmd K.

Focus and typewriter scrolling

Focus (Cmd Shift .) hides the binder and the inspector and dims every paragraph but the one you are in. Esc or Write brings everything back.

Focus mode: one paragraph bright, the rest dimmed

Typewriter keeps the line you are typing in the middle of the window, so your eyes stay in one place. Switch it on from the top bar, the View menu or Settings > Editor.

Right-click

Right-click on the page for what you can do with the word or selection under it:

On a word the spellchecker has underlined: its suggestions and Add to dictionary. See Spelling and readability.
Look Up opens the Mac's dictionary for the word.
Cut, Copy, Paste and Paste as plain text, which leaves the formatting of whatever you copied behind.
Add comment and Insert footnote.
New research note and Add as a name for, for a selection. See Characters and places.
Find the selection in the document.

Right-click works elsewhere too: on documents and folders in the binder, on cards, on projects on Home, on snapshots in History and on the boxes in the inspector. Each offers what its own buttons do, so there is nothing new to learn.