Mac mail inbox view only?

You can get it approximately like the iPhone by grabbing the vertical wall between the list of emails and the email view pane on the right and dragging it to the right until it disappears. Then you'll only have the list of emails and will have to double click on any email you want to read to open it in its own window.

No idea what it looks like on a phone, but in Mail's View menu try the Hide Options there.