Staples' Easy button, $5.95. I sometimes use this to reassure pediatric patients that the new skin test devices (ComforTen, etc.) are virtually painless and provide quick and accurate results, with no needles or blood draw. They are happy to hear "That was easy!" after the procedure.
"Staples Foundation for Learning" will donate proceeds of the product sales, up to $1 million, to Boys & Girls Club of America (2 AAA batteries included).
Sand Timer for allergy skin test
Amazon.com: 3 Minute Plastic Colored Sand Timer - 12 Pack: Toys & Games. Quote: "Flip it 3 times and you're done with the skin test" (an allergy skin test takes 10-15 minutes).
Educational Toys for Allergy Clinics