ByWord is another app I’ve tried for posting. It works well on a Mac, and it has support for posting to a self-hosted WordPress blog (publishing to WordPress requires a in-app purchase, which I bought). I just realized that it has support for uploading local image files. It detects them in the markdown document, and uploads them to the server. This might be the thing I need to use. As a test, here’s a picture from onbaord the schooner Seaward