Since your question is about Illustrator for iPad, I have moved this from the Illustrator forum where you posted.
I haven't found Construction Guides on the iPad yet. On the Desktop, you can turn on guides for common angles, such as 30°, 45°, etc., or even for any angle you want, such at 17° or 23°. Smart Guides will help you on stay on this angle while drawing.
Illustrator for iPad does not had Image Trace yet. Add your comments here: