by Melissa Hincha-Ownby for MotherNatureNetwork The proliferation of smartphones, and the accompanying applications, has made life a lot easier for business travelers. With hundreds of thousands of apps to choose from, though, how do you know which apps will be useful and which apps will simply clutter your phone? Over the last two years I’ve taken dozens of business trips and based on my first-hand experiences, I’ve narrowed the list down to 13 must-have apps for the business traveler.   Travel Apps 1. TripIt: TripIt was the first travel app that I downloaded because I had a hard time keeping track of both my travel accommodations and my husband’s. TripIt is a free app that creates an itinerary for your trips based on email confirmations. You forward your email confirmation to TripIt and the app creates an easy-to-use itinerary based on the trip. With one tap you can look at your flight information, hotel reservations and car rental information. No more digging th…