Classifications are used to categorize values into groups and report at the group level. For example, you can classify all Paid Search campaigns into a category like “Jazz music terms” and report on the success of that category relative to metrics like Instances (a.k.a. Click-throughs), and conversion to success events.

Mobile classifications are enabled after you enable App Management > App Reporting.

Pre-requisites: Product Administrator rights.

Steps:

• Visit Edit Settings -> App Management -> App Reporting in Report Suite Manager.
• Click on ‘Enable Latest App Reports.’ at least (see below). You can enable others as well based on your requirements.
• A confirmation window pops up after it is enabled. 

After some time, re-login to the Adobe Analytics, and Mobile Classification page will be available (Edit Settings -> App Management -> App Classifications)