To check or force the update of your app you can tap 5 times on “my account” title in the my account feature.
If the message is “no update available”, your app is already up to date.
If the update cannot be done, it means you have to republish your app (new build).
Please note : the app updates itself automatically (unless the app build is too old) . This method has been added to allow apps owners to check the update status of their app.