Someone on YouTube is asking me whether it's possible to use the wireless mic at the same time as having a wireless connection to the Mimo app - as mine hasn't arrived I can't try that - I assume it's possible but maybe it isn't - anyone know for sure?

Forget it, I think it was user error.  

Presumbably the mic works over bluetooth rather than wifi, anyway?

I can confirm that the mic and the phone can be connected wirelessly at the same time. The mic icon shows in the top left corner.