Why does it take 24 hours for friends to show in simcity?

I added a friend yesterday so I could get an item that he had and I rebooted my device its an iPad 2, still did not show up on my list. Today showed for the first time but the getting of the item had  well past the time. Today I just added another friend who has an item, and he to is not show. I only realized after he message that had the item was not on my friend's in FB  list but he sent me the request so not get this item either, If I got to wait 24 hours. some one told me to log off go out of the game come back and log back in and all well then show. said thats on Kindle well it work on the iPad 2?

Please answer my questions who knows as no one so far has done yet