I cannot speak for the Steemit personnel but I would surmise they are working on it. I would believe they are not just sitting around wasting time...but maybe they are.
As for the app, I dont know what you mean? Steemit.com is an application...it is an interface....just like busy.org is an app...
Unless you are referring to mobile...I think what they had developed was trashed since it wasnt turning out very good...that opens the door for other apps to fill the void.
Please tell me if I misunderstood your meaning.