Your app can use the Google Play Core libraries to support the following UX flows for in-app updates:
Flexible updates provide background download and installation with graceful state monitoring. This UX flow is appropriate when it's acceptable for the user to use the app while downloading the update. For example, you might want to encourage users to try a new feature that's not critical to the core functionality of your app.
Immediate updates are fullscreen UX flows that require the user to update and restart the app in order to continue using it. This UX flow is best for cases where an update is critical to the core functionality of your app. After a user accepts an immediate update, Google Play handles the update installation and app restart.