Apps are incredibly useful no matter where you go, but they need to be the most use when you’re on the go. So make sure you download a combination to your phone, and put some thought in for your future self here.
If you’re someone who’s always on the go, you need to make sure your phone is just as capable of being constantly at use as you are. This means adding some extra battery life in, always having a connection to keep in touch with friends, family, and business associates, and having all the apps you’d ever need if you were stuck out in the wilderness (but still managed to have some kind of 4G signal at the same time…).