How do I delete screen recording from my IPhone?

A few months ago I downloaded a screen recording app that would eventually allow me to record my screen. I used it for a bit, (it worked) and then I deleted it. In the process of setting up this screen recorder, I added the record button to my control centre, so when I swipe up from the bottom of my screen it is one of the options in that option bar.

I can still successfully record videos and save them to my camera roll using that button, even though I have long deleted the app. I’m worried that if it can still record after I’ve deleted the app, it may be able to record my screen without my permission/knowledge of it happening.

I just don’t want any of my personal information being stored on some data base that I’m blissfully unaware of meanwhile this third party app is plotting to steal my identity.

I really hope someone can help me with this - any response will help x ❤😓