How to get this icon thingy off of the home screen on my iPhone?

I had an iPhone for a while that had a broken power button, so one of my friends fiddled with the settings somehow to get this little square icon to always stay on my homescreen that would allow me to turn my phone off, access the control centre, access Siri, go back to the home, etc. It had a number of functions. ANYWAY… So I recently got a new phone and transferred my old info onto it, and the little icon thingy also got transferred, but I don't need it anymore. Does anyone know what I'm talking about and how to get rid of it?

That "thingy" is called Assistive Touch.
Go to Settings>General>Accessibility>Assitive Touch and turn it off. Very simple to do.

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