PKWare does have a mobile app for iPhone, iPad, and Android:

http://www.pkware.com/software/securezip/securezip-reader

At present, it appears to be for reading encrypted compressed files. The product description includes "Send via E-Mail" but there are no details. The app is a free download.

I don't know whether PKWare is developing an app that can be used to create encrypted and/or compressed files on a mobile device, whether iOS or Android. It seems to me that "mobile" devices will eventually have the equivalent of the CPUs that are currently used in laptops and desktops, most likely as SoC.

Would you consider, for example, the Microsoft Surface that will run Windows 8 Metro to be a "mobile device"? It's appears that it will be as mobile as an iPad and far more powerful.