Myself and other app developers I've spoken with have heard this before: "Your apps look too basic, too boring." I am wondering if there is an online course, or a blog or a book that I could refer to, to learn how to make my apps look and act wonderfully and give them excitingness. I am not a UI/UX person but I did take a Coursera UI design course, which confirmed what I already thought about UIs. Apparently there is more to learn... Like Socrates said, I know I don't know. As a solo app developer, I don't have a budget for a UI/UX person to help me, but I am willing to learn it myself.