Remove 32-bit Apps
iOS 11 brings an end to 32-bit apps. If there are any apps on your iPhone that are 32-bit, then you won’t be able to use them in iOS 11 since they are no longer supported. This shouldn’t be much of an issue since most apps have already been updated for 64-bit devices.
You can easily identify the 32-bit apps installed on your device. Open the Settings app and go to General > About. Tap on Applications. Here you’ll see a list of all the 32-bit apps that are installed on your device. If there’s any update available for these apps, then go ahead and update them, then come back to this list to see if the app has been removed from the list or not. If there is no arrow or action when pressing “Applications” your apps are all up-to-date and require no further action.