If you are using 32 bit apps, you will need to upgrade it or you won’t be able to use it as apple has decided to not support it on its iOS version 10.3
Are you are using 32 bit apps on iOS 10.3? you must have gotten a pop up that says the app may slow down your iPhone,you can still run the app and you won’t probably notice any slow down of device that you have warned about.
What is 32bit apps and 64 bit apps
32bit and 64 bit in simple terms is amount of data a processor can handle so by using 64 bit you get faster performance. Since it can process more data per second, It lets device use its full potential of 64 architecture.
What this means to you 32 bit apps and 64 bit apps
if you are using older devices that are based on 32 bit architecture(e.g iPhone 5 or below ), you won’t be able to upgrade to the next version of iOS. If you are using 64 bit based devices ( iPhone 5s ,6,6s,7) you will need to update all the 32 bit apps to 64 bit apps in order to use