boiling temperature of water isn't constant. It depends on the air pressure. Only for the mean pressure at sea level it will be 100°C (212°F). Therefore with rising altitude the boiling temperature will drop quickly. On Mount Everest it is 68°C (154 °F) only. Why bother? The time to cook eggs depends on the temperature, which means above sea level it takes longer to cook them to perfection.
So far you could have used my Boiling app to calculate the boiling temperature for any altitude. But many modern smartphones come with a internal pressure sensor (e.g. the iPhone 6, the Nexus 4). So with the new version of Boiling you can calculate the water boiling temperature for your current air pressure which not only depends on your current altitude but on the current weather as well.