From the Bear team and built on the Bear 2 editing engine, Lettera works directly against the Mac file system — open a single file or a whole folder as a workspace, with no proprietary database. Markdown syntax hides when you’re not editing so the document reads like a preview while you stay in the source, and it supports MathJax, inline images, tables, ePub export, and version history. Currently a free public beta via TestFlight.