Should I write an iOS app for 64-bit devices only?

Question

iOS

Hello everyone, so far a complete noob in development for iOS. For android, there is already a written application that I posted on the playmarket, now I want to write for iOS, in connection with this, several questions arose.
I know that iPhones starting with the 5s model have a 64-bit architecture, and older models only support 32-bit. Hence the question is whether it is worth writing immediately for 64, that is, for modern iPhones, and in general, what is the fundamental difference when writing an application in xcode for 32-bit and 64-bit? If only in the inclusion of some libraries, then it's not scary. If there are some separate sections of code for the 32s and you need to write something separately for the 64s, then I will clearly write only for the 64s. Explain, please. It also depends on what I should take for testing either iPhone 5 or 5s.

Answer 1

If you do not work with bit structures, then you will not notice the difference between 32 and 64.

Answer 2

well, yes ... ios11 is coming ... and all 32bit applications are already blocked in the applestore =). so the choice is yours!