Disclaimer: I was a non paying user and used it just to try out some code in dotnet entity framework and postgresql (at $work I only ever get to touch sql server but for hobby projects I thought it would be nice to do something that doesn't require paying Microsoft).

Bit io is awesome. It just works. I mean so does elephant but bitio has more storage. I never got very far with my learning and never did tadvanced db concepts like cross apply though so it was just simple entities and tables but it worked just fine and the best part, no credit card required on file.

Fly sounds nice but I don't feel so good about having to give them my credit card number...