I am using Ubuntu 20.04. I wanted to install Unity-tweak-tool, but a few seconds after it began installing I canceled the installation and then an app was added to my launcher and it's mostly like "nautilus" with the name "Files" and a purple icon and different customization and background.
I want to uninstall it or at least remove its icon. I have searched "unity-tweak-tool", "Files" and in /usr/share/applications for its icon to remove and the command: dpkg --list, but none of them exist.
The app's icon and name:
The left one is this new app and right one is nautilus:
The package that you installed is Nemo, that is a file manager (born as fork of Nautilus) and that is used in some Ubuntu flavours like Ubuntu Budgie. Also Linux Mint uses it.
I don't know which kind of dependencies brought you to install it, but you can remove it by: (flag suggested in a comment by @AkibAzmain)