You can refresh particular entity by passing entity name. like
So Is it working for you? If yes. Then post your solution as a answer and accept it to help community.
How will you differentiate the apps here ? I need to refresh the entities of specific app.
I'm not sure about app level entity bcoz
debug\refresh forces a refresh on splunkd resources ( all registered EAI handlers). If you have specific type of changes like dashboard XML files, Navigation XML File OR configuration File I suggest to use entities. Entities can be specified by appending them via URI parameters (As I posted previous comment).