Adding multiple SmartApp's?

I am new to this and may be being thick, but…

I have added a Sonos SmartApp (it is the Sonos SmartThings Labs App) that allow a message to be played over a Sonos speaker to announce someone coming home. This is tied to a single mobile phone.

When I attempt to add another instance of this SmartApp, tied to a different phone (So I can have a specific messages for each instance), I just get “an unexpected error occurred”.

I have tried making sure the names are different and I have tried removing all and adding each configuration individually. Both work individually, but not if i try to load 2 instanced.

Am I being thick or is this just a, not that smart, SmartApp (In which case can you point me to a better one).