Brian, I agree. The problem with apps, unless you have a reasonably modern phone with a good amount of memory, is that you end up with too many apps/more than the phone can manage. We have just replaced a 5 year old phone - too old for the upgrade of an app we were needing.
Happened to me twice yesterday. Both with the same seller. Both closed but no idea if they sold. They just vanished from my watchlist. I am using a desktop computer.