This is not an app but an iOS library that can be used to display a Scalable Vector Graphics (SVG) file. According to WikiPedia an SVG file is: "an XML-based vector image format for two-dimensional graphics that has support for interactivity and animation." Programs that can export to the SVG format include vector graphic programs like Adobie Illustrator and InkScape.
The main graphic file format supported by iOS is PDF but because iOS does not let you get inside of and alter PDF contents once loaded, many programmers are looking to an SVG library. Since all major vector graphics programs support the SVG format it allows easy transfer of vector graphic content from design to app deployment.
Like iOS functions designed to handle PDFs, this library allows coders to easily load an SVG file and display it on screen. It also allows full access to the object structure so data can be easily changed. Because it displays using the iOS's Quartz 2D graphics, engine graphics are sharp at any scale or orientation.
Here is a portion of the object structrue of the library: