A new iPhone application turns a smartphone into a lab to pinpoint foods that may cause allergic reactions. The iTube, invented by college professor Aydogan Ozcan, takes a picture of the food, then uses a tiny test tube to analyze a sample for the chemical makeup. The test takes about 20 minutes, but some are not convinced. "I definitely have concerns and skepticism and warnings for my patients who use any of these things. As far as I know, they are not accurate enough to rely on," said food allergist Scott Sicherer.