What it means is that your material is under your ownership.
However, the package that you produced is that section 6 talks about. They have the "do so grant, to Ludei, a royalty-free, non-exclusive, worldwide license to use, reproduce, modify, publish, list information regarding, edit, translate, and make derivative works of all such User Content and your name, voice, and/or likeness as contained in your User Content..."
the licence listed is for the purpose of adding a logo which counts for "reproduce, modify, publish, to also list name, likeness...." this is because the outputted version is a derivative product.If you don't agree to the modifications and reproduction, then they can't legally produce the package APK or IOS version.