Facebook has released Facebook Camera app which is a standalone photo-sharing app for iPhone in the App Store after acquiring Instagram for $1 billion last month.Facebook Camera app is no way a replacement of Instagram.
The app enables you to share your photos on Facebook and see what your photos which are being shared by your friends in feeds.

As per the press release of Facebook-
See friend’s photos all in one place – When you launch the app, you’ll see a feed of just great photos from the people you care about. You can swipe to see more of any album or tap to enlarge an individual photo.
Share multiple photos fast – Now you can quickly share multiple photos all at once instead of having to post one at a time. Just select the shots you want to share by tapping the check-mark on each photo and then hit post. You’ll have a chance to add a caption, say where you were and tag friends before you share.
It’s also easy to edit photos with new tools like the ability to crop, rotate and add filters to any picture in your camera roll.”
You can download Facebook Camera app from App Store for free and is compatible with iPhone 3GS, iPhone 4, iPhone 4S, iPod Touch 4G, iPad 2 and iPad 3.
Download Facebook Camera for iPhone and iPad