Could the app that's 32 bit run on 64 bit, iPhone 5S?

Question

If doing this, $(ARCHS_STANDARD_32_BIT), like answers here suggested, Arm64 architecture in xcode 5.1

Will these 32 bit app be compatible with 64 bit and run well on iPhone 5S or even later?

Answer 1

Yes they will run on an iPhone 5S. The iPhone 5S will load the 32-bit framework into shared memory on the device, and run the app using that.

But it is worth while supporting both 32-bit and 64-bit architectures to reduce the memory usage your app consumes on a 64-bit device - even if you're not using any 64-bit specific features.