NASA is an iPhone application released by USA's National Aeronautics and Space Administration. It is loaded with all sorts of information about the past and present missions of NASA, and is ideal for space enthusiasts plus anyone who has a slight interest in space exploration and wants to find out more.
The organization of the information presented in the application is very intuitive. One can search the content based on a particular mission or scan through the image and video libraries. While scanning through either of these libraries, one can search using keywords or filter the images and videos by source of the videos.
For images NASA included images from the Hubble Telescope.
You can use this application to track path of any NASA satellites include the International Space Station.
NASA included Twitter feeds from its various Twitter accounts it has. These can be accessed either from the dedicated Updates icon in the bottom toolbar or from within a mission or satellite's page.
With a price of FREE this is definitely a must download from Apple's iPhone App Store for anyone who are interested in space exploration.