Google Translate - Translates user’s words as they are spoken into a device’s mic. Has a database of 50 languages.
Google Goggles - Search by taking a picture. Users can point their cell phone cameras at paintings, famous landmarks, barcodes or QR products, or popular images. If Goggle finds it in its database, useful information will be returned.
Tipulator - Makes tipping easy even with split bills.
Tripit - Combine all your travel reservations in a single locations.
RoadNinja - Always know what is coming up at the next exit and compare gas prices at upcoming exits.
Wi-Fi FInder - Directions to your nearest source of wireless internet. Comes with an offline mode so that users can download maps.
ExpertFlyer - Get notified when seats become available.
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.
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.
EHU - Helps campers and caravanners keep track of the electrical output of their assorted travel gadgets to avoid overloading the circuit.
Waze - Provides user submitted traffic report to offer the fastest route for current road conditions.
Lemon Wallet - Allows user to store a digital copy of all cards – ID, insurance, loyalty, and payment card, so that they can be accessed whenever needed.
Google Maps - Accurate GPS enabled maps along with voice navigation.
MoneyPass - Access locations of over 20,000 surcharge free ATMs either by entering an address, a zip code, or using your current location. 
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.