The app duplicates the egg-shaped plastic toy that became a must-own sensation like Beanie Babies, TickleMeElmo and Furby after it was first released in 1996 in Japan.
The limited availability of certain products -- the iPhone now, Furbies in 1998, TickleMeElmo in 1996 -- gives them an extra allure that increases the value of the product, Yarrow said.