Just attended a talk by Rick and he named an easy translation app that you can view offline. Missed the name. Help
i have no idea which one rick would suggest but we have used jibbigo and word lens. both are different from the usual 'dictionary' type apps.
word lens ( while not perfect) is amazing, it allows you to read words as you pass your phone/ipad etc across the text. eg: menus etc.
has to be seen to be believed.
both of these we use off line.
hope this helps.
I also have no idea which app Rick recommends? You might have a look at Google Translate which offers app's for both iPhone and Android platforms (and perhaps others). However, last time I checked, they only had off-line capability for Android phones.