The content is stored locally on the device, letting you read and participate in the discussion even if there is no network connection. When you do have a network connection, the database replicates new entries from the server to the app, and any entries written by you on the device get replicated to the Domino server.
Replication happens in the background on a schedule configured by you.
You can configure the app to replicate with multiple discussion databases.
Tablet users have an extended navigation experience, making it easier to jump from discussion thread to discussion thread.
The app is open source and available on openntf.org.