I wrote this christian app for Android using Java, some years ago, as a personal project, this native application has grown to have over 100K downloads providing service to thousands of users monthly.
This application has had some challenges, because it does not only provides daily lectures in English, Spanish and Portuguese, but also plays audio podcasts in the background, lecture customizations, packages downloads, and all of this has required to build a custom api with a remote server and Database to be able to provide service for that many people.
You can check the app in the Play Store clicking the link below
