I know that my Pioneer app to control my VSX-53 is using an app that works off of 32-bit. Which gave me a little warning that it will slow down my iPhone/iPad.
That didn't bother me as I rarely used that app anyways.
But now it looks like in a future iOS update that warning will become something that breaks the ability for the app to work.
[Link: 9to5mac.com]KOT