What kind of application is not targeted at both teens and adults?

Youtube, twitter, bluesky, whatsapp? Every app with a social aspect will be used by teens. And no, tiktok is not "only for teens" or "specially targeted at teens", nowadays everyone uses it and creates content on it.

Came here to post this.

If you run (say) a restaurant, you get big spikes in business from TikTok videos in ways you don't get from Facebook or Instagram or others.

TikTok is the platform everyone is one right now.