"The best camera is the one you have on you" goes the refrain, so instead of having to pull out my cell phone and find the camera app to get that already gone shot of my 10-year-old, now it's easier.
Say you want to go see the Woolly Mammoth they have in the museum, your smartphone (through theapp) will show you how to get there, once you have arrived, your phone will push to you the information about the Woolly Mammoth and other content related with that exhibit.