If you are registered with the Apple developer program you may have received the following email.
At WWDC 2017, we announced that macOS High Sierra will be the last macOS release to support 32-bit apps without compromise. Support for 32-bit apps is not available in iOS 11 and all 32-bit apps previously installed on a user’s iOS device will not launch.
Download the latest beta versions of iOS 11 and macOS High Sierra, and make sure your apps support 64-bit so users can continue to run your apps on future versions of iOS and macOS. For more information, read the 64-Bit Transition Guide.
Apple Developer Relations
What this means is that if your apps is a 32bit app if will no longer launch on iOS 11.
Examples of behaviour are demonstrated here: https://www.macrumors.com/2017/06/06/32-bit-apps-no-longer-supported-in-ios-11/
You can validate the IPA manually if it is built for 32bit or 64bit architecture by using OSX with Xcode installed.
Here is an example using validation latest version of SecureWeb by Citrix:
Unzip the ipa
daniil$ unzip SecureWeb-10.6.0.17.ipa
Use file command to validate the binary
Payload/WorxWebEnterprise.app/WorxWebEnterprise: Mach-O universal binary with 2 architectures: [arm_v7: Mach-O executable arm_v7] [arm64]
Payload/WorxWebEnterprise.app/WorxWebEnterprise (for architecture armv7): Mach-O executable arm_v7
Payload/WorxWebEnterprise.app/WorxWebEnterprise (for architecture arm64): Mach-O 64-bit executable arm64
As you can see SecureWeb is built for both 32bit and 64bit architectures
Alternatively the lipo command can be used
daniil$ lipo -info Payload/WorxWebEnterprise.app/WorxWebEnterprise Architectures in the fat file: Payload/WorxWebEnterprise.app/WorxWebEnterprise are: armv7 arm64
This can also be validated from a device via the following screen
Settings -> General -> About -> Applications
Applications listed in this section will not run on iOS 11.
64bit Transition guide available here: https://developer.apple.com/library/content/documentation/General/Conceptual/CocoaTouch64BitGuide/ConvertingYourAppto64-Bit/ConvertingYourAppto64-Bit.html