An AppImage install leaves nothing system-level behind. Python and Kivy are bundled inside the AppImage file. A completely clean AppImage uninstall can be done with:

rm ~/Downloads/Libiry-*.AppImage 
rm -rf ~/.config/Libiry/ 
rm -rf ~/.cache/Libiry/ 

Leave ~/.kivy/, unless you’re certain you have no other Kivy apps.

An install.sh install touches system directories and requires sudo to clean up:

WhatLocationHow to removeDanger
App + Python venv/opt/Libiry/sudo rm -rf /opt/Libiry/None beyond losing the app
CLI launcher/usr/local/bin/libirysudo rm /usr/local/bin/libiryNone
System icon/usr/share/pixmaps/libiry.pngsudo rm /usr/share/pixmaps/libiry.pngNone
Desktop entry~/.local/share/applications/Libiry.desktoprm ~/.local/share/applications/Libiry.desktopNone
User icon~/.local/share/icons/hicolor/256x256/apps/libiry.pngrm ~/.local/share/icons/hicolor/256x256/apps/libiry.pngNone
Settings~/.config/Libiry/rm -rf ~/.config/Libiry/Irreversible
Cover cache~/.cache/Libiry/rm -rf ~/.cache/Libiry/Safe
Kivy config~/.kivy/rm -rf ~/.kivy/Caution — other Kivy apps may be affected
System packageslibsdl2-dev, python3-venv, etc.see belowHigh danger

The uninstall.sh script handles everything, except system packages and ~/.kivy/. Do not remove system packages blindly. The packages installed by install.sh (python3-dev, python3-venv, libsdl2-dev, etc.) may be needed by other software. Running: sudo apt-get remove python3-dev python3-venv libsdl2-dev sudo apt-get autoremove could remove dependencies shared with other apps. Only do this if you know these packages were not on your system before installing Libiry.