Egg Timer by MaginSoft is a handy application for your Windows Phone if your trying to boil an egg just right. The mango app is based on scientific methods and taps into your Windows Phone's GPS to calculate the time an egg needs to cook in order to reach your desired doneness.
Egg Timer is laid out in simple fashion with fields that have you set the size of the egg, starting temp (refrigerated or room temp), your altitude, and desired doneness. Doneness is based on the condition of the white/yolk and ranges from begins to set/liquid to rubbery solid. If you're not sure of your altitude you can tape the GPS button to have that setting determined by your location.
Settings cover your weight, temperature, and altitude units of measurement and what type egg class standard you prefer. Once you get all your preferences set jut right and are ready to cook, just tap the "cook it" button at the bottom of the screen to start your timer.
Egg Timer is a nice, simple cooking app for your Windows Phone. There is a free trial version that is limited in functionality (you can't choose all the cooking options or access the GPS) with the full version running $.99. You can find Egg Timer by MaginSoft here at the Windows Phone Marketplace.