Hi,
The fortigate app offers dashboards with prebluit searches and graphs, allowing you to directly get useful inormation about what's happening in the device without the need to manually searching into the data. In the roadmap are additional features like Data Model integration to allow automatic information acceleration and easy graphical searches via pivots, and CIM compliance to allow the use of generic Apps intended for security management, network mananegement, etc.
This Splunk app doesn't connect directly to the Fortigate IOS, but get the information from fortigate syslog facility via TCP port as I think you configured your device. In order to get it running, you just need to create a new index called fortigate and configure you fortigate(s) to send syslogdata to port 513 in your Splunk instance. You should start seeing information into the Fortigate Splunk App.
Hope this helps.
