Angie, it seems to be an app that lets you locate the ISS using an iPhone or iPad. I don't have either of these so haven't tried it out.
In general, if people are interested, it's to know when they can see the ISS where they are viewing, and there are other ways of doing this.
On NASA's Spot the Station
you sign up for alerts for phone or email, and there is a tracking map and other information.Heavens-Above
can tell you if the ISS will be passing over the location you ask about, and provide details. My article on Heavens-Above – website
tells you what other information you can get from the site.