What program is used to make iOS apps?

Answer 1

iOS apps are made with Swift 3. Check out this link if you're interested in learning app development:
https://www.sololearn.com/Discuss/242006/?ref=app

Answer 2

https://www.sololearn.com/Discuss/242006/?ref=app

Answer 3

Xcode or Appcode. You can look at both, you can make a lot of stuff in Xcode, it's Apple's official IDE.