Not a solution for everyone, but I am selfhosting and using FreshRSS. One of the extensions is Readable which will fetch the entry’s URL and parse it using either Readability or Postlight Parser to replace the content of the entry and make all of it available in the reader.
This is an important criteria for me. If I can’t read the full article without leaving the reader and without a WebView, I won’t keep the RSS feed.
Not a solution for everyone, but I am selfhosting and using FreshRSS. One of the extensions is Readable which will fetch the entry’s URL and parse it using either Readability or Postlight Parser to replace the content of the entry and make all of it available in the reader.