Tempura Baja Oysters - Saw these pics the other day and have them next on my list of things to make.
Thai Shrimp Burgers - these are super simple to make, yet a bit fragile, but are quick and really good. Also not something you'll find anywhere else. To make into an app, just make them sliders, or they can be served like crab cakes.
Conch Fritters - who doesn't love conch fritters!