How to determine which users and what apps are using summary events created by my searches?

[krishnani]

1) How to evolve the summary searches and I want to know if anyone uses the summary events created by my searches?

2) How to determine what apps are using summary events created by my searches?

3) How to determine who's using data from a particular summary search?

[s2_splunk]

I don't know what you mean by "optics summary searches", but you can get information on who runs what search from the _audit log. You'll have to refine this to meet your needs, but maybe this gets you started: index=_audit action=search search="*index=*" | table user search
This will only work, if your summary indices are not searched by default, i.e. the user has to explicitly specify the index name.