Open Source RSS.app Alternatives
RSS.app is described as 'Create RSS feeds from almost any website. Build RSS feeds for your own website or use it to monitor your favorite sites. Most websites already have RSS feeds, but many do not'. There are more than 10 alternatives to RSS.app for various platforms. The best alternative is PolitePol, which is both free and Open Source. Other great sites and apps similar to RSS.app are morss.it (Free, Open Source) and Full-Text RSS (Freemium, Open Source).