What you linked is basically an elaborate phishing scheme. The exploit allows the installation of non app store apps, but that doesn't mean the installed apps can escape the sandbox. The worst thing it can do is try to trick the user into entering passwords into the app's fields. As far as malware goes it's pretty benign.

There have been a handful of cases of iOS malware over the years, but no serious exploit has been widespread. For an exhaustive list see here: https://www.theiphonewiki.com/wiki/Malware_for_iOS

The most wide spread malicious apps are generally apps that access private apis but manage to get through Apple's review process and onto the App Store. They can be far reaching but again they can't breach the sandbox which means the absolute worst thing they do is upload your email address to some server or try to trick you into giving away your password. I still stand by my assertion that the average user doesn't need to worry about malware on iOS.