In most cases, you do
not need an AV app on non-jailbroken iOS devices. Please review your iOS Security, Find my iPhone and iCloud for backup.
However, there are some Antivirus for iOS available, by not by Apple themselves.
For example:
Avira Free Antivirus for iOS -
http://www.avira.com/en/free-antivirus-ios
Lookout Free/Premium -
https://www.lookout.com/
These companies may provide additional services (ie. Prevent Data loss or Theft) included for free or require a fee, but they will require you to register an account with them. Note, Apple can provide this for free as it's built-in to iOS/iCloud.