"Travel apps are great, but watch out for roaming charges," I wrote in 2009. Five years on, little has changed. Data roaming remains too expensive for dawn-to-dusk app use in most countries. Fortunately, some apps work fine without an internet connection. So, even after you switch off mobile data for take-off, you aren't flying blind.
Some guide apps work entirely offline. Pre-loaded maps locate you using GPS, which uses no data, then find the restaurant, hotel or sight you require. Sometimes you need to use the map service on the app before you travel to make sure it is ready-downloaded, or cached. To check this has happened, test before you travel by switching on 'airplane' mode and trying to use it before you travel.
Travel 'utilities' often rely on a 3G or Wi-Fi connection, however. Google Translate and other translation apps are less powerful without internet, for example. Visual translator Word Lens (Android, iOS, Google Glass; free) is one language app that works perfectly offline. Point your smartphone camera at foreign words and an English translation appears on the screen. Word Lens can handle simple blocks of text, such as menus, newspaper headlines or road signs, in French, Spanish, German, Italian, Russian or Portuguese. In May, the app developer was bought by Google, so expect more integration with Google's vast translation capabilities soon.
Currency converter XE .
The Telegraph, London
