RSSme - RSSme is free, lightweight and user-friendly RSS editor.
Documents by Readdle - A central hub for all your files.
Feed Launch .NET - Feed Launch .NET is an open-source feed editor for RSS 2.0 and ATOM 1.0 Feeds.
Lunamaker - Lunamaker is a paper notebook with digital courses on drawing and sketching.
Feeder by Reinvented Software - Feeder is for creating, editing and publishing RSS feeds on macOS.
PDF Professional - PDF Professional is a feature-rich PDF Ultimate Solution for reading, annotating, form filling, editing, signing, and converting PDFs on your Mac, iPhone and iPad.