Multi-Platform App Publishing

I need assistance in publishing my desktop app, available on Windows and Mac, to the following platforms:

- Microsoft Store
- Azure Marketplace
- Apple App Store
- Google Play Store

My developer accounts for all stores are already set up, which should streamline the process.

Ideal skills and experience:
- Proven experience with app publishing on all mentioned platforms
- Familiarity with the specific requirements and guidelines of each store
- Strong understanding of the packaging and submission processes
- Ability to troubleshoot and resolve any issues that may arise during publishing

Please provide examples of similar projects completed and estimated timelines.