I don't think that should be a priority now. Maybe when Mycroft is a little more mature and we have a little less to do, this could be an interesting project, but definitely not now.

On a more general note: Do people really use voice assistants? I know they are everywhere, but i never really made use of OK google on android or Siri back in my iOS days, Cortana on Windows 10 is the most useless piece of C, i don't own an Amazon Echo or Google Assistant. It would be an insane amount of work to make it usable, and then i think many people would just look at it as a fun (or not fun, depending on how good it is) toy rather than a useful tool...

I'm not sure if there's a chance of winning this one. Maybe just an app, that doesn't integrate with the phone? Might be a good project for someone in the community.