For the record, I purchased the VirusBarrier app this morning to try it out on the iPhone and let you know my factual experience.
1) It costs $2.99. If it catches something - malware or anything over the next year, I would not call it a waste of money in my opinion. If nothing happens, I would consider it insurance.
2) I tested an email message with a PDF attachment to see how this operated.
Due to Apple's iOS, the method that it uses to re-direct the PDF file to be scanned on the iphone is cumbersome in my opinion. One has to select a menu button to see the "Open in VirusBarrier" button. I found this was available only after I had already opened the PDF file on the iphone so it was visible.
I emailed Intego to see is they could talk to apple to include this feature in the iOS directly to make this more usefull and automated. I also asked them if any of the features are automated when selecting something to open.
I have yet to test it using Safari to browse to a web site that should be blocked if it has a phishing scheme or malware, etc..
3) Without automation, I would say this VirusBarrier App would be more useful with those using the iPad and editing/saving documents in its memory in my opinion. I don't see anyone editing documents on an iPhone.
Otherwise, Apple's iOS may limit the sales of this app due to the lack of automation.