Seatguru - Shows the best seats on every plane and where power ports are located.
Knapsack - Plan your trip and later share memories.
Waze - Provides user submitted traffic report to offer the fastest route for current road conditions.
Trip Journal - This virtual travel scrapbook will also create maps of your various explorations as long as your GPS in turned on, geo tagged with pictures, videos, and notes.
iMuseum - A web tracker that searches via GPS the closest museums in your immediate area. Updates museum news and exhibition info regularly.
Passbook - Passbook is an application in Apple’s iOS that allows users to store coupons, boarding passes, event tickets, store cards, generic cards, and other forms of mobile payment.
Dineoutcheap - Gives diners a fast and easy way to find deals.
ExpertFlyer - Get notified when seats become available.
FourSquare - Turn on this app upon arrival and see a list of tips from those who have been there before you.
WhatsApp Messenger - Provides the ability to send data (including pictures, videos, sound clips, and GPS tags as well as text) via Wi-Fi for free to people anywhere in the world.
EHU - Helps campers and caravanners keep track of the electrical output of their assorted travel gadgets to avoid overloading the circuit.
Google Wallet - Send money from anywhere to a friend in the US who has an email address.  Store loyalty programs in Google Wallet and leave the plastic cards behind.
Google Maps - Accurate GPS enabled maps along with voice navigation.
Urbanspoon - Shake your phone and the Urbanspoon slot machine will suggest local popular east via the GPS in your phone throughout the US, Canada, UK, and Australia.
HopStop - Offers public transport information on 68 of the world’s biggest, busiest metropolitan hubs.