Keynote

Use vertical text in Keynote on iPhone
Keynote supports vertical text in shapes and text boxes, so you can enter and edit text from top to bottom, such as in Chinese, Japanese, and Korean. Each new line appears to the left of the one before it.
To use vertical text, your presentation must be formatted for Chinese, Japanese, or Korean, or you must have at least one of these languages on your device’s preferred language list. To learn more, see Create a presentation with the formatting of a different language and Change a presentation’s language and formatting.