Its not an app, they are assets. So should be available for any platform.
Grotto Escape II Art Pack
A downloadable game for Windows, macOS, and Linux
Pixel Art Pack containing a complete environment for your #gamedev.
The pack contains Tilesets and Sprite-sheets and some animated sprites.
This is an extension of the original Grotto Escape Pack.
Click download now to get access to the following files: