The September update rounds out signing: draw, type or photograph your signature — or shoot it with your iPhone — add initials and signer profiles, and let "Sign Every Spot" walk a form's signing spots one by one, filling the date in the same step. Certificate signatures join in: sign with a keychain identity (or create one) and every signed document is verified when it opens.
Editing takes a step forward too: the page's own printed text can now be re-set in any font installed on your Mac, with the font embedded in the file, and bookmarks are fully editable. The welcome window has become an animated tour of the app.
Direct-download copies update themselves; the full list of changes is in the changelog.