What publishing an app to the App Store and Google Play looks like

Creating developer accounts on both platforms (Apple Developer Program, Google Play Console) — this requires registration, an annual fee with Apple, and verifying the identity of the company or individual.

Preparing all marketing materials: the icon in exactly prescribed dimensions, screenshots of the app's screens, a description of features in the target market's language, and a mandatory privacy policy available at a public address.

Checking compliance with store rules — for example, if the app has in-app payments, it must use that platform's prescribed payment system for digital products; if it collects personal data, it must clearly explain why and how it uses them.

Submitting for review — Google Play most often does this automatically and quickly, while Apple almost always includes a manual review by a person testing the app, which makes the process slower and less predictable.

Incomplete or unclear feature descriptions that don't explain clearly enough what the app does.

A missing or incomplete privacy policy, especially if the app collects any personal user data.

Non-functional or unfinished parts of the app the reviewer discovers while testing — any "work in progress" screen or error leads straight to rejection.

An unclear or incomplete user sign-up process, especially if the app asks for sensitive permissions (location, contacts) without a clear explanation of why they're needed.

Preparing all these elements in advance, before the first submission, saves days or even weeks of waiting for a re-review after a rejection and fix.