iThoughts on iOS -- a mind mapper that has been around for a "long time" in iOS years -- this week has a minor update that adds an outline view. With folding -- in honor of Bill. The outline is not editable. Folding the outline also collapses the selected parent node in the map. It's a convenience for browsing large maps. Other mind mapping apps on iOS are prettier. However, I don't think any competitors match iThought's broad feature set.

MindNode had this for some time already. Looks similar. I never found it very useful for outlining though...

Mindnode's text outline option came out for the Mac in 2015 with v.2, and the iOS 'list view' (with checkboxes) arrived with v.5 late last year, I think (could be wrong).

Like iThoughts, Mindnode/iOS does not let you edit in outline view.

https://mindnode.com/support/userguides/ios/outline

But in the outline view on Macs you can delete nodes.

https://mindnode.com/support/userguides/mac/outline