Android Release
Google Playstore
Android Developer Console: https://play.google.com/apps/publish
After creating a new code-signed APK, upload it to the Android Developer console beta testing section under the APK area.
See: https://developer.android.com/distribute/googleplay/developer-console.html
Amazon
Amazon Developer Console: https://developer.amazon.com/appsandservices
When a new build goes into production on the Google Playstore, upload the same APK to the Amazon Application store.