Android requires that all apps be digitally signed with a certificate before they can be installed. In order to distribute your Android application via [Google Play store](https://play.google.com/store) it needs to be signed with a release key that then needs to be used for all future updates. Since 2017 it is possible for Google Play to manage signing releases automatically thanks to [App Signing by Google Play](https://developer.android.com/studio/publish/app-signing#app-signing-google-play) functionality. However, before your application binary is uploaded to Google Play it needs to be signed with an upload key. The [Signing Your Applications](https://developer.android.com/tools/publishing/app-signing.html) page on Android Developers documentation describes the topic in detail. This guide covers the process in brief, as well as lists the steps required to package the JavaScript bundle.