Lovense/WeVibe/Satisfyer/etc.

in-app controls for remote-controlled sex toys, for Xtra
could also create affiliate program and discount codes for users.

imagine doms being able to control subs' vibrating plugs through the app. if pitched only for Xtra users, that could wildly increase user activity and have something no other site does yet, as far as I know

could also partner with Lovense/WeVibe/Satisfyer/etc. by showing their ads for certain products