This feature has on many platforms mcafee web gateway, untangle, safedns, fortiguard, iboss, smoothwall, barracuda, sophos filtering, titan filtering, comodo domeshield, opendns, netnany, flashstart, dnsfilter, mimecast web security, clouduss web-categories, forcepoint, codeproof, scoutdns, goguardian etc.
Example categories: alcohol, dating, drugs, news, shopping, search engines, chat apps.
Pi-hole team can add this feature to upcoming version. Some platforms like nextdns, cleanbrowsing has implemented way for this to toggle as per-service basis eg: skype, reddit, ebay,... i don't feel interest about it then above said method cover every services around the world belong to each category (and not several).
Free services to get,
- Sensei (currently use by OpenSense) - https://www.sunnyvalley.io/sensei/
- ShallaList - http://www.shallalist.de/ (side panel has download option)
http://www.shallalist.de/categories.html (currently use by squidguard, dansguardian)
Statics chart for Dashboard
Cloudflare also has such facility. maybe there's way to get benefit from it.
https://developers.cloudflare.com/gateway/reference/categories (list of categories)