Some of these wallpapers have become a part of the official UI kit and made it to the final release.
...and some of them were used in real world.
OS Aurora
Aurora OS is a Linux-based smartphone operating system derived from Finnish Sailfish OS. The operating system has its own application store and it is integrated with the majority of government's infrastructure. I had an honour to participate and help with developing such an integral part of the OS Aurora. While, not all of these solutions were implemented and made it to the final release, I still feel like it was a decent effort.