Just an FYI, the existence of content in an Apple Store does not mean that the content is in anyway approved by Apple. Rather, it was approved by a single reviewer. You can submit something, get denied for a specific reason, and then resubmit and get a new reviewer, and get through without an issue.
Furthermore, the existence of content does not mean your content/app that has the same feature will be let in. Heck, during review, you can comment on the fact that other content/apps has or does exactly what you are doing, but that does not matter in any way.
Furthermore, the existence of content does not mean your content/app that has the same feature will be let in. Heck, during review, you can comment on the fact that other content/apps has or does exactly what you are doing, but that does not matter in any way.