Tech Review: Travel apps act as your co-pilot

Planning a vacation or business trip overseas? Whether you want to call home for free, find a U.S. official in a foreign land or convert your currency or your conversation, these apps make excellent travel companions.

XE Currency

(iOS, Android; free)

Your greenbacks may be welcome everywhere, but you can bet dollars to doughnuts you won't always get a great exchange rate at hotels and shops overseas. This app has up-to-the-minute conversion rates for virtually every world currency, so at least you'll know whether the exchange rate you are quoted is realistic or a ripoff. The app works offline, using rates automatically downloaded the last time you were online.

Tango Messenger

(iOS, Android; free)

Like its rival Skype, Tango allows users to make free voice and video calls from anywhere in the world if they have an Internet connection and the people they call also have Tango installed on their mobile device or PC. We tested several calls from the U.S. to Hong Kong, and video and audio were smooth and stable every time. Video calls are data intensive, so unless you have a good international data plan, wait until you are on a free Wi-Fi network before calling home from overseas.

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Smart Traveler

(iOS, Android; free)

This official app from the U.S. State Department has continually updated travel warnings and alerts for more than 100 countries. Although the app can be clunky and slow, the lists of addresses and phone numbers of U.S. embassies and consulates throughout the world can be a potential lifesaver if you find yourself in trouble or simply lose your passport.

Google Translate

(iOS, Android; free)

This popular app, updated last month, translates more than 70 languages. Type or speak a word or phrase, and the app yields a written translation. It also offers an audio translation, so you can pass the device to the person you are talking with and have a back-and-forth conversation. Snap a picture of a document, road sign or menu, and the app can translate that, too. Once you download the app, you don't need an Internet connection because it works offline.

Tech Bytes

Cyber rattling

As the long Thanksgiving weekend ends, Americans will go from standing on line on Black Friday to buying online on Cyber Monday. Considered one of the busiest e-commerce days of the year, Cyber Monday is expected to break records tomorrow. Marketing firm Forrester predicts online sales will grow 15 percent from last year to $78 billion, sparked by promotions such as free shipping and steep discounts. -- Peter King

PayPal accepting gift cards

The main attraction of giving and getting gift cards with the American Express, Visa, MasterCard or Discover brand is they are good virtually anywhere -- except at some Internet retailers not set up to redeem them. PayPal has unveiled a new service that allows users to pay with gift cards online, as long as the retailer also accepts PayPal. Simply use your prepaid gift cards through PayPal Checkout. -- Peter King

Twitter ads target TV watchers

Twitter added a tool that lets advertisers target users who are posting about television shows. The feature allows networks and consumer brands to promote tweets to users discussing specific shows, even if the advertiser isn't running a spot in the TV program. Twitter can directly boost TV ratings when members use the site to share their immediate reactions to a show, a Nielsen study from August found. -- Bloomberg News