The What's new page collects descriptions of changes in the app, newest first. They stay here for good, even after you read the notification about them.
What's newYou will find it at the bottom of the side menu, right above Profile.
Read the latest release
Each release has a date, a title, a one-line summary and a list of changes grouped by topic. Some end with a button that takes you straight to the new feature.
Come back from a notification
A new release is announced by a notification under the bell. Clicking it opens this page right at that release.