Hi, I'm not sure if it's been suggested before. I tried to check.
There's so much activity on the Feeds these days. Just think it would good if we could bookmark any post we wanted to look at later again instead of strolling through posts. This will be especially helpful if we want to keep track of challenges that go on over a number of days. I think adding a Section for Bookmarked Posts will make it easier for users to reference back to as they need.