When travelling through foreign countries it is likely that you will need to talk to certain people in those countries. Those people are likely not English speakers so you are going to have communication hiccups. To quell the issue there are many language translation apps available.
Language apps are useful as they can be installed onto a phone or tablet and kept with you at all times. A good example is the iTranslate app for Apple iphones and tablets.
This app has 90+ languages included, voice output and input, dictionaries and Romanisation. An impressive suite of features that all come in useful when dealing with a foreign language.
The voice input can be used to translate your voice and transform it into text. This text is then translated into another language. This is especially useful for translating phrases and much faster than deciphering a phrase book.