Is the Sonos Boost supported using the new app?

I have an old Sonos Boost lying around that I used to run in an old S1 system. I no longer use S1.

As I don’t need it anymore I’ve decided to sell it and thought I would do a quick test to make sure it still works. 

I have reset it but the new S2 app cannot find it when using ‘add speaker or component’.

Are they no longer supported in S2?

I have searched these forums but can’t find much info. 

Any help would be appreciated.