The addon Clear Cache on Admin Login has a single functionality: clearing the cache on admin login.
When you install this addon, this functionality will be active. When you uninstall this addon, this functionality will be inactive. Hence no setting page for this addon.
When this addon is active, the action that Super-User logins will trigger clearing the cache. Nothing happens when other users login.
This addon clears the cache when a Super-User logins. After installing this addon, nothing happens, until you log out and log in again.