If you have have lost faith in Instagram after its whole Terms of Service saga—even after it reverted back to the original version—there is a way to “free” all your precious Instagram pictures and transfer them safely to Flickr.
Web-based app FreeThePhotos “allows you to easily transfer your photos from Instagram to Flickr by simply logging in and clicking a button. Think of the kittens, think of the breakfast plates, think of the converse shoes. Free the photos.”
However, if you currently hold a free Flickr account, you would face some limitations when using this service—only your last 10,000 Instagram photographs would be migrated and you would only be able to view the last 200 pictures.
Even if you have no wish to give up Instagram yet, this is still a good way to back up your carefully color-filtered images.