Chill Subs is fascinating. They allow you to have a nice author profile, list multiple publications, and search for markets. They have recently added a search by newly added markets option. Which is something I had thought about requesting.
I am beginning a blog series of #ShortStory #Submission programs I use.
I am sure there are some I don't know about.
Here is my partial list: Aswiebe, Chill Subs, Duotrope/Duosoma, Moksha, Oleada, Poets & Writers, SFWA, Submittable, and The Submission Grinder.