It's actually 10 categories with several applications listed for each: 1. Media Server 2. File Sync Server 3. Virtualization Platform 4. Ads Blocker 5. Image Hub 6. Home Automation 7. Security Center 8. News Aggregator 9. Password Manager 10. Gaming Console

Full details in the following article: https://linuxiac.com/best-self-hosted-raspberry-pi-apps/

Cheers, Peter