Downloading TextNutSD 1.0.5 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. The application is categorized as Productivity Tools. The actual developer of this free Mac application is Edgenius.
From the developer:
TextNut SD is an easy-to-use markdown editor. The tool supports advanced markdown for images, footnotes, or tags. It allows you to switch rich or markdown editing mode on-the-fly without losing your document format. You can export or preview the markdown document in PDF, HTML, and RTF with customizable styles.
You may want to check out more software for Mac, such as PDFMergeThing, NanoCount or iTeXMac2, which might be related to TextNutSD.