I don’t have an iPhone or an iPad but I know many people who do have and use iThoughts HD. They are always very complimentary about the product. Today one of those people, my younger brother as it happens, emailed me that they have released version 2 of iThoughts HD. Click the link to find out the details of the improvements around topic images, hyperlinks, text styles and width plus improvements to the notes view.
Why mention iThoughtsHD here, because it is compatible with MindManager files. You can share files via DropBox and other cloud services between the mobile device and your desktop or laptop.