Building a mobile application involves dozens of small tasks beyond writing code.

Authentication, navigation, APIs, notifications, permissions, and testing usually get most of our attention.

Then, as the application gets closer to release, we remember something else.

We need the app icons.

Not just one icon, either.

Android and iOS have different requirements, and preparing the necessary image files can become surprisingly repetitive.

Let's look at how app icons work and how to simplify the process.

Why can't we just use one PNG?

Imagine you've designed a beautiful 1024 × 1024 pixel logo for your application.

It looks great.

So why can't you just add that PNG to your project and let the operating system handle everything?

Technically, platforms and development tools can resize images.…