I don't think it uses your relays, which is a shame.
But also - IIRC the /used-apps section only shows apps remembered in this particular browser. I've stumbled upon this myself recently, will be fixing it all soon. 

 thanks man, I have nip-89 and nip-31 almost ready to go in Habla but running into this issue. hopefully we'll sort it out soon and get amazing interoperability. 

 Amazing!