New York City restaurant The Mermaid Inn has launched an iPhone app that catalogs over 200 varieties of North American oysters. The app also lets you rank different oyster types you've already tried. The full version costs $1.99, but you can test run a 60-oyster version for free.
Check out the app
"Much like wine, the flavor of oysters changes based on weather, region and method of cultivation. Oysterpedia, created by The Mermaid Inn restaurants in NYC, was designed to take the guesswork out of ordering oysters as well as to provide a reference tool for the oysters you have already tried. "