They did, it's called primal, but the client is insecure because you have to paste in your nsec
Also, there is an ecahs project where your npub automatically recieves ecash when you login but the client has to enable it right nostr:nprofile1qqs9pk20ctv9srrg9vr354p03v0rrgsqkpggh2u45va77zz4mu5p6ccpzemhxue69uhk2er9dchxummnw3ezumrpdejz7qgkwaehxw309a5xjum59ehx7um5wghxcctwvshszrnhwden5te0dehhxtnvdakz7qrxnfk