Ahead of the launch of iOS 11, there were several signs suggesting 32-bit apps would no longer be supported in the new operating system, which has been confirmed with the release of the first iOS 11 beta.
In January of 2017, the first iOS 10.3 beta featured an even more serious message when launching a 32-bit app, which specifically read “This app will not work with future versions of iOS.”
Any 32-bit app will refuse to launch and instead show an alert pressuring the developer to release a 64-bit update. Older iPhones and iPads with 32-bit CPUs cannot update to iOS 11 at all.
For iOS 11 users worried that their favorite apps are about to be cut off, you can check which apps do not support 64-bit architectures via Settings on iOS 10 or iOS 11.
Go to General -> About -> Applications. If you have 32-bit apps installed, you will be able to tap on Applications and see a list of your obsolete software. Whilst on iOS 10 these apps still launch, on iOS 11 you can only hope that the developer continues to maintain the application and releases an update.
Apple has also started the transition for macOS to drop 32-bit support. It will require new apps and updates submitted to the Mac App Store to support 64-bit apps in 2018.