Real time voice changer module

How about a real time voice changer module? A possible application is to search for vulnerabilities (or just for fun) using social engineering by voice communication system. It should have microphone input, line out connectors, a microphone and a speaker, i guess. It should be capable to change voice in real time with a number of setups and presets, of course.

Wouldn’t it be easier just to use your smartphone?

That’s the main question and I have no answer. Is there some scenarios where the module will be better than a smartphone?