There are tons of web services out there where you can save content content such as images, text and web pages. Services that are basically visual notes app. There may be some similar apps for the iPad but nothing is really as minimal and clean as Curator.
Curator allows you to collect and organise all sorts of stuff and put them onto large cards which are like categories. You can search for stuff from across the web or save content from various other places like your camera roll, Dropbox, Instagram and many others.
The great thing about Curator is that it can be used how you like, whether it be for presentations or even a portable portfolio. It is mostly a visual app so images bring it to life.