I thought this is important for as many people to see as possible. A few years ago, Apple switched to 64 bit processing and storage. Shortly thereafter, they started requiring all new apps and updates to be switched to 64 bit. Recently, they started culling old apps that had effectively been abandoned and were not 64 bit. You may see the warning upon launching an app that it may slow down your iPhone. This is because it’s a 32-bit app. In iOS 10.3, there’ll be a stronger warning and you’ll be able to find out which apps are 32-bit. And as of iOS 11, those 32-bit apps will no longer work. Better check them now. Bob
Good advice from Bob who also sent in this link to show you how to check your apps.