4. Entrain
Nothing spoils a trip more than good ol' jet lag. Whether you're a seasoned traveler or just now joining the mile high club, prep for jet lag using Entrain foriOS and Android. Developed by researchers from the University of Michigan, the app monitors your body's circadian clock using your smartphone to know what time of day it is to help reduce the suffering of jet lag.
Plug in your sleeping habit data and the time zone you're traveling to, and the app calculates a schedule specifying when you should stay in bright light, low light or be in the dark. The app then helps you gradually shift your sleeping schedule to lessen the impact of skipping across all those time zones to help you get the most out of your travel.