Take a look at Creating Custom View Tiles.
Specifically this section:
If you want to create a Jive-hosted custom view tile, you must specify a local URL for the "view" property (and for the "config" property if you have a configuration UI), and specify that your tile is "internal" using the following JSON property within your tile definition:
This allows you to create a tile without the need for an integration service.
On the other hand, if you want to host a service, simply omit this dataProviderKey property and specify an http URL for the "view" value in definition.json.
Does this translate to custom Add Ons/Apps? I noticed this is for Tiles, and looking at the json files, I don't see any properties predefined with 'dataProviderKey'.