Question

xcode, swift, and appy pie are all tools for doing what?
writing code in java
creating smartphone apps
creating apps to run on a desktop or laptop
writing code in c#

Explanation:

Xcode is an IDE for Apple - related app development, Swift is a programming language for iOS and other Apple platforms, and Appy Pie is a platform for creating mobile apps. They are mainly used for smartphone app creation.

Answer:

creating smartphone apps