After your app has been published in AppCenter, you can issue a new update at any time by creating a new release. This will begin the submission process again for your app.
Screenshots are uploaded to the AppCenter screenshot server at publication time. The URL referenced in your AppData.xml file will be automatically replaced during publication and any changes you make to images hosted at the remote URL will not be reflected in AppCenter.
You must add accurate release descriptions to your appdata.xml file when publishing an update. For more information on formatting, see the FreeDesktop.org AppStream documentation for the tag. The version in your release should match the latest version submitted to AppCenter.
Release descriptions should be accurate, concise, and written for a typical user of your app—focus on user-visible and user-understandable changes, and simplify or omit technical "under the hood" changes. For example, a good release description might be:
Support for WebP images
Option to maintain aspect ratio when cropping
Main view now loads twice as fast
Updated French translations
Other code cleaning
…while a poor one would be:
Fix bug #1234; rewrote method to be async
Linted all the code, removed trailing whitespace
Previous release descriptions can remain in your AppData in perpetuity; AppCenter may use these to display cumulative descriptions between an older installed version and the latest version.