SimpleMind Desktop is a mind-mapping tool that turns your Mac into a brainstorming, idea-collecting, and thought-structuring device. It connects to the similar SimpleMind for iPhone/iPad app.

Progressive Downloader is a powerful and flexible download manager.

MWeb can handle professional-level markdown with support for markdown extensions. It provides publishing to various social networks and blogging formats, as well as various preview themes. It also has two work modes: external, which allows the addition of external folders; and library, designed for note-taking and static blogging.

PhotoMill helps you convert a bulk of images into the most popular image formats, give your files meaningful names, watermark with text and image, adjust photos (brightness/saturation/exposure/grayscale/etc.), fit geometry (scale/crop/trim/etc.), remove private metadata, add your own copyrights etc. Also, PhotoMill is a great batch metadata editor, renamer and photo browser.