Just by simply checking the various endpoints of Design Automation it's not obvious that you can share your app bundles and activities with other Forge apps.
The POST aliases endpoint of both app bundles and activities accept a parameter called "receiver" where you can provide the Client ID of the Forge app that you want to share the given version of your resource with.
It only accepts a single Client ID, so if you want to share a given version of your app bundle or activity with multiple Forge apps, then you need to create a separate alias for each - see picture on top.
Once you do that, the resource becomes available for the other Forge app:
Follow @AdamTheNagy Adam Nagy joined Autodesk back in 2005 and has been providing programming support, consulting, training and evangelism to external developers. He started his career in Budapest, then worked in Prague for 3 years and now lives in South England, UK. At the moment focusing on Inventor and Fusion 360, plus cloud and mobile related technologies. Adam has a degree in Software Engineering and has...