I want to reset an app on my iphone so it loses all its data. I already uninstalled and reinstalled the app, but everything is still there?

I want to reset an app on my iphone so it loses all its data. I already uninstalled and reinstalled the app, but everything is still there? - 1

Some are tied to your account so you either make a new account or you email the developer and ask them to delete it.

Depending on the app, reinstalling isn't going to do anything as the data is stored elsewhere.

Even when you erase an app from your phone it may be stored in your iCloud and preserving its data there. Try logging on a desktop into your iCloud and seeing if it is there and erase it.