Here's some general information in case other users stumble across this thread:
A "package ID" or "application ID" is meant to be uniquely identify your application. The package ID belongs to your organization, company, product, or personal brand. It is often derived from your domain name. For example, our website here is https://dropsource.com. As such, the package IDs we use for our code start with
com.dropsource. At Google, their code falls under the
com.google package. If your company's website is located at awesome-company.com, your package ID would be
Once you have the base package established, you then nest things further based on a specific product, tool, application, or service. For example, if your company is making a mobile app named "Amazing App", then your package ID for it would be
Running with this pattern allows you to ensure that your mobile apps never conflict with other company's mobile apps. It is also why Google won't let you submit an application to the Play Store if its declared package ID already exists in their system. The "default" package ID declared in your Dropsource Project should be changed to match your organization before attempting to submit it to the Play Store.
I'd also like to note that once you've deployed the application to the Play Store, you can't change it later.
Please let me know if you need any clarification!