"Cleaning" an iPhone for international travel

I see that the privacy declaration of QR Reader indicates it does not gather browsing history, which is promising.

Also it has an NFC scanning feature, which could be useful, if combined with the option to confirm visiting a website. In my opinion it is too easy for a nefarious agent to trigger an NFC action on compatible smartphones. An NFC tag can be the size of a postage stamp (remember them!)