How to change the size of a single app icon

All icons are the same size. Are you sure you don't have a widget on your screen? The smaller, square widgets might seem like a large icon.

How to add and edit widgets on your iPhone - Apple Support

FGNadar wrote:

https://discussions.apple.com/content/attachment/7491953a-efe7-465f-b045-8d0157f6182e

As IdrisSeabright correctly stated, those are not apps but rather widgets. Hold on the widget until you see remove.

FGNadar wrote:

Got it, thanks!

You are very welcome!