May I know what are the difference purposes of an add-on vs an app and how it works?
I understand that an app has its specific UI but how about an add-on? Is there a URL that provide some description about developing an add-on?
Isn't it also true that there isn't a technical difference to Splunk between an App and an Add-on, and the distinction is just in how they are used (as defined in the answer above)?
Actually there is a very specific technical difference - whether the app is flagged to be visible in the UI so that it shows up in Launcher and in the Apps menu, and then when launched, has its own nav structure. It's an app if this is true, an add-on if not.
Add-ons can have views, but those must be globally shared and pulled into the nav of a visible app to be seen.
It is however true that the word add-on is not formally part of Splunk's configuration or management UI.