Another app I love is Google Translate. While I've used Google Translate from time to time on the web, it's even more useful on the phone since you probably already have it with you when you need it.
It's nicely integrated with speech and with texting. While it's not perfect, it's a great resource beyond pointing and gesturing. Just make sure it gets the speech to text right: e.g., :"robotics trip" vs. "robotic strip". Common words and simple phrases come through OK if spoken carefully.
The selection of languages is also pretty amazing, and it works in both directions in a conversational mode. When I was at Goodwill South Florida, I showed them it could not only handle Spanish but also Hatian Creole.
So this is one more tool just to have for those times when you just can't find the word in Spanish or don't have a clue how to say it in Korean. And the price is right.