This app was mentioned in 3 comments, with an average of 1.33 upvotes
I'm a strong advocate of graphic design over illustration. Not that illustration is bad or anything, but for an indie developer where time is so valuable, you can make great looking games with very minimal stuff if your grasp of layout and typography is on point.
Examples:
https://play.google.com/store/apps/details?id=com.sm.smove&hl=en
It's basically a 3D version of Smove.