Vectornator Pro for iOS is an amazing graphic-creator app and is now free!
It usually costs $8, but has now been made free. We assume that may be for a limited time, as there don't seem to be any in-app purchases put in place to monetize the app in any other way. So, give it a spin if you care for on-the-go graphic design.
The app has a few example templates thrown in there to get you going. It can be a bit jarring at first, as it's based around placing shapes first and filling them with colors, adding blurs, and manipulating them later. But if you have experience with vector graphic tools, you'll feel right at home!