Aniyomi or Animetail?

I'm trying to figure out the exact difference between the two apps. They both have the same UI and function the same so what is the difference between them and is there a superior one? Which one is the newer one or the more reliable one as I'd prefer to stick to that one in case the other one gets shut down or something.

I want to choose one as I have downloaded episodes of the same show on both apps and they're taking up storage so I'd rather just have one with my downloaded episodes.