I've added to Pocket Casts, which is the app I use. I'm looking forward to listening tonight.

For iTunes, you must provide your artwork at a certain size and your feed must be 'iTunes-compliant', which basically boils down to some extra tags that no other application uses. I'm not sure if Soundcloud provides those or not, but most likely they do. Your feed only contains one episode, however.

For my shows, iTunes took about a week to approve. Once approved, you're added to the directory and then never have to mess with it again. Ensure that your shows are flagged appropriately regarding the explicit tag.

I think they've loosened up now, but not too long ago, you had to submit a new show through iTunes. Now I think they offer a web-based way to do it.