I'm using the Splunk cloud trial version. Just for the sake of practice, I want to create a Demo App, but I can't find any option to do so. Is it necessary to have Splunk Enterprise to create an app?
You cannot install apps in Cloud demo but Splunk support can (and will, if you convince them you have a good reason for it). You need to open a support case and be sure to select Cloud so it gets to the right team.