What is android-app in Referrals?

One of my websites has a lot of traffic from “android-app”.

I see that Simple Analytics website also gets traffic from this referral: Website Analytics dashboard of Simple Analytics

Do anyone know what it relates to?

It’s traffic from other Android Apps that don’t set a referrer. The only referrer we can get is android-app. It could be Instagram, X, TikTok, or any other app.