A bad news for those who used iThoughts as a (temporary) companion to Scapple on the iPhone/iPad. The developer has ceased activity, and the software can no longer be purchased. Not only that, but if it had been moved from your iDevices to the cloud, it can no longer be downloaded from the App Store.
This is bad not only because we don’t have anything to work with Scapple projects on the iPad, but also because it was a really excellent app per se.
MindNode is a good mind mapper for the ipad (Mac too). It reads OPML files which is a standard interchange format used by most outlining/mindmapping apps.
IThoughts allows you to export mind maps in OPML format, which can then be used in other mind mapping or outlining applications.
Try SimpleMind Pro. It’s available for all platforms (iPhone, iPad, Macs & Windows). I have used it on Mac & Windows a few years now and find it excellent. It’s perpetual licence (one licence for Mac & Windows versions) and the developer releases regular updates. There is also trial & free versions for the platforms so you don’t have to pay to try it out.
I’ve been owning SimpleMind and MindNode since forever (this latter being my favorite when needing a pure mind map).
The particularity of iThoughts was that it could immediately import Scapple files. It was not true compatibility (it only worked one-way), but it was the quickest way to carry a project with you. Edits could be then manually moved to Scapple when back at the Mac.
In no case these apps are the equivalent of Scapple, both as philosophy (notepad or whiteboard where you can freely stick unconnected ideas, vs. hierarchical mind mapping).