Correct me if I'm wrong, isn't it just an RSS reader? (I deleted it from my phone as I used it like only once.) I'm not sure if it has a "Mark All As Read" button, but if I remember correctly it doesn't. That's probably one reason I never really used it.
As far as alternatives go, I would recommend Google Reader. It syncs with your Google Reader web account so it's very easy to manage and add feeds. And yes, it has a "Mark All As Read" button.
Correct me if I'm wrong, isn't it just an RSS reader? (I deleted it from my phone as I used it like only once.)