Lot many times we would not be known if the client has the specific application license or not.
We can ask the client is one way. If you have access to the back-end for the production Instance. Then you could know with following query. This is the Other way.
All the applications which are Installed status are license one.
,DECODE (status, ‘I’, ‘Installed’, ‘S’, ‘Shared’, ‘Not Installed’) status
FROM fnd_application_all_view a
, fnd_product_installations i
WHERE a.application_id = i.application_id
ORDER BY 1;