Ask HN: Temporary Apps?

What if on your iPhone there was a folder/group of temporary apps? These apps would include store apps for when you walk into a store and you see items to purchase and a map. Or even a travel guide app for the country you just traveled to. These apps would appear when you walk into their vicinity area and go away when you leave.

Also, what if the apps were not downloaded, but viewed and downloaded for a short period of time like a website?