nostr:npub10npj3gydmv40m70ehemmal6vsdyfl7tewgvz043g54p0x23y0s8qzztl5h has a client for managing the cloud relays he rents out (it's his own cloud, not Amazon or whatnot). You can also self-host and use his client, as it's FOSS.

https://relay.tools/signup