If you don’t use categories on your blog, this plugin will stop news readers/aggregators from displaying “Category: Uncategorised” or similar.

Disable Feed Category

This simple plugin disables the "Category" field in your RSS/Atom feeds.

Prasanna SP

Just like the normal WordPress site feed, wordpress categories and tags also has feeds. The category feed is located at <code>site.url/category/categoryname/feed</code>. This plugin automatically adds the RSS feed link to the current post categories after the post content. By default the plugin shows category feed link on single posts. You can change it’s settings to show it on other pages, such as archives as well. You can change it’s title in WP-Admin –> Settings –> Follow Category Feeds.
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Follow WordPress Category Feeds

This plugin adds link for the category feeds after post content.

Disable Feed Category vs Follow WordPress Category Feeds