[mzltest]

Good idea.Is this app designed for "blood banks"?If yes then you can make a interface that connects hospitals with the blood bank to let the hospital know what kind of blood is availanle,and when in short of blood they can let blood bank know what type of blood need to be donored ,making infoemation exchange easier.If you decide to make a account system for donors you can involve the donation ranking and reward points -- that's what we have here.