Meet the BeepEgg: a singing egg timer that lets you prepare perfectly boiled eggs every time. Just throw it into a boiling pot with your other eggs and wait for it to start singing. It plays a unique tune when the eggs are soft-boiled, medium-boiled, or hard-boiled.
BeepEgg works for medium to large eggs. It monitors the outer temperature to calculate the core temperature of your eggs accurately. Costs about $20 at this time.