Nice list. I tried at some point to analyze html using a tree-sitter grammar and generate a list of articles, index them, and be on alert every so often for new entries.
RSS feed could be generated automatically with some AI code generator (or tree-sitter query generator), and just parsing the elements of the page.
Eventually i failed, but also i didn't try hard enough.
1. https://lighthouseapp.io/ - feed reader combined with bookmarking
2. https://lighthouseapp.io/tools/feed-finder - tool to find RSS feeds (https://lighthouseapp.io/blog/deep-dive-finding-rss-feeds)
3. https://lighthouseapp.io/tools/newsletter-to-rss - tool to convert newsletters to RSS feeds