I'm not sure if any other users have some issues, but I often do with the iOS app.

Sometimes there are syncing issues, but recently I have found a problem with the "advanced study" of one list. It seems whenever I attempt to study from one list, it is obvious the words are from a different list.. why is this? It defeats the purpose of the single list study. I have tried to clear out the local data and relog in on the iPhone/iPad and this problem still arises. Actually, after I did that and try to "advance study" on my ipad no lists come up!! Why? Obviously I have a bunch of lists. This essentially makes the iPad app broken....

Can the programmers please look into this?

I sent you an email about this; not sure what's going on, but it sounds like some weird data corruption is going on with your local copy, so deleting the app and reinstalling might be the thing to try next. Sorry about this.

Received the email. Deleted the app and reinstalled. It got my lists back.

Hope the dev team and look into it and patch in a future update.