We're working on making this a lot easier in a future release!
Your new and updated activities should now be available from your Harmony Hub entry in Yonomi. Tap the underlined "Activity" if you'd like to confirm that the updates are present.
Harmony Hub activities will not appear as individual entries in the Things tab of Yonomi.
If your Harmony Activities are still not appeaering, there may be something wrong with your setup and further investigation may be necessary. Please see this article for more information: https://yonomi.groovehq.com/knowledge_base/topics/my-harmony-activities-arent-appearing-in-the-app