Reeder works with multiple backend providers, Feedly being one of them. I do the same, have had a great experience.

Feedly's mobile app has pretty bad UX (or at least that's been my experience every time I try installing it on Android).

For example, in the article list view, there's a single basically-identical swipe left/right gesture to...

  * mark single article as read
  * mark single article as unread
  * mark all articles on page as read
  * mark all articles on page as unread

The difference between marking a single article and marking all articles seems to be based on how far you've swiped, but if (for example) you don't release your swipe and keep moving your finger further after it's marked all as read, it suddenly does the opposite and marks all articles as unread. The direction of the swipe (left or right) doesn't seem to control whether you're marking read/unread -- it's (in my experience) been completely arbitrary what it decides to do, regardless of swipe direction. It's ridiculous how painful it is, and it's basically been this way for as long as I can remember.

The app has really poor bulk management of articles, so I just turn to other apps. Currently I'm using News+, which has superior bulk management capabilities... but it hasn't been updated in forever (and is buggy in other ways).