btw out of curiosity I've tested a few google mobile apps while traveling. my experience:
translate - needs internet and failed reading cyrilic.
google maps - offline caching didn't work at all, I didn't know how to get to my cached maps as when I start maps it raises a message that I need internet connection and didn't let me go further.
google drive - I pressed 'offline' and wanted to create a document and it says I need internet connection. lol.