What is the difference between
Splunk for ServiceNow(https://apps.splunk.com/app/1228/) and
ServiceNow Integration for use with Splunk Enterprise(https://apps.splunk.com/app/1770/)
If you look at the very first line of text that appears when you click the link to "Splunk for ServiceNow" - https://apps.splunk.com/app/1228/
* This app has been replaced by the supported app at https://apps.splunk.com/app/1770/
While not directly answering your question, it seems to indicate which one you should be using.