So by now you have converted your idea into fascinating working app and have tested it by downloading it locally to your mobile. If you are pretty satisfied with the performance and features of your application, you should now look forward to upload it to the Google Play Store where other users can download and try it. Uploading your app to the play store will make you popular and if it is really worth trying then more and more people will download it and will praise your work.
Every app you publish must have a Version Code and a Version Name. You can set these in the App inventor designer under the Properties Panel for the
Version Code is an integer value that will not be visible to Google Play Store users. It is used by other apps to check if your app has been upgraded or downgraded. It defaults to 1 and should be increased by one with every successive change whether it is a major change or a minor change.
Version Name is a String which can be anything you would like. It is defaulted to 1.0. A common structure is a decimal number which is increased by 1 for every major change and 0.1 for every minor change. For example, an initial Version Name could be 1.0 which can be updated to 1.1 after a small change and 2.0 after a larger change.
You will need to increase the Version Code and change the Version Name of your application when you upload a new version to the Play Store.
Once you are done making your app, you can download your Android .apk file as follows:
This will prompt you to save the application somewhere. Once you have the .apk downloaded, you are ready to begin the publishing process.
For a complete Guide about How to Get Started with creating a Publisher account on Google Play and Getting started follow the link : Get Started with Publishing App on Google Play