VirusBarrier puts a malware scanner on your iPhone so you never have to worry about viruses and malware. iOS is pretty safe and secure, as there’s no known malware that’ll make your iPhone bug out and die. iOS limits what apps can do, but because iOS limits apps can’t autoscan your file system or run scheduled checks, instead when you receive an attachment in Mail, you can hold down on that attachment and “Open in VirusBrier” to scan for malware. Additionally, the app can scan other files on the iPhone, files on DropBox, MobileMe, FTP servers and more by adding a remote location.”]
Source: https://gizmodo.com/virusbarrier-for-iphone-protect-your-iphone-by-scannin-5843076