OP already knows about this, check his second sentence (or paragraph if you wish).
If my memory serves me right, Radar Relay and Token Jar also allow you to do that. But don't know if they disabled it now.
It's still
possible with TokenJar, but looking at
their trading volume, I doubt that being listed there will be of any help.
As for Radar Relay, then according to
this, getting listed is free but it must be approved by the developers (you must meet certain requirements). I can't find any recent article that says otherwise.