Comment 1 for bug 648574

There's already an autocomplete feature in development that will propose you addresses that you already entered.

I understand that this would be great to have a live suggestion box in a phone but it consumes a lot of network resources and that's why only desktop computers have it.

Tile packs only contains... tiles!
That's just bitmaps and there will be no text data inside these packs.
It's not possible right now to provide a full auto-suggest nor offline navigation because we don't use vector data.
It is in our plan to support it in the future but that's a lot of work so it will not be very soon.