Question: How can I create professional-grade app icons without hiring a designer or spending a lot of time?

The Icon Generator is a good option, producing unique and pro-level app icons and logos in less than 30 seconds. It's got a big library of graphics, a range of styles and automatic color palette generation. The system produces icons in 1024x1024 HD resolution, and you keep full rights to the icons and commercial use. It's easy to use, so you can use it for A/B testing and other situations where you want to try lots of variations.

Another option is Iconify AI, which also produces unique, pro-level app icons in a few seconds. It's got 11 styles, automatic color palette generation and high-resolution output in 1024x1024 HD. The tool uses a credit-based pricing system, with a 100% refund guarantee and full rights to the icons you generate, including the right to sell them and copyright.

If you want something more elaborate, Appicons is integrated with Photopea for editing and produces high-resolution PNG files. It's got three pricing tiers, including a Standard option for $10 that lets you generate 100 credits and 600 designs. That's a good option for developers and designers who want to generate unique and professional app icons without having to hire a designer.