Instagram now lets you bookmark posts for later viewing
Now you’ll see a new bookmark icon underneath posts in your feed. Simply tap it to save a post to a new, private tab on your profile. There you can see all the posts you’ve saved and they’re only visible to you.
When you stumble upon a funny video you want to remember, a new outfit you like or even inspiration for an upcoming vacation, you can now keep track of favorite posts right from your profile.
http://blog.instagram.com/post/154465796577/161214-savedposts
that’s a feature that lot of sites are offering now