GMCMultiImage
GMCMultiImage is a set of classes you can use to show pictures for which you have multiple images in a range of sizes.
For example, you can use GMCZoomingMultiImageView
to present a picture that the user can pan and zoom. It automatically downloads (or loads from cache) the appropriately sized image for each zoom level.
License
GMCMultiImage is available under the MIT license. See the LICENSE file for more info.