I actually implemented a mobile web version at first with the up-sell of buying high res images. I wasn't happy with the images it was producing though because I forced 1 setting for all images being converted for the sake of ease-of-use for the user.
But this was a mistake. Not all photos are the same: Some photos looked better with smaller/larger cells, as a diamond grid, with different color settings, etc.
Server costs and complexity grew too: (nginx, nodejs, rabbitmq). The algorithm is CPU intensive and not fast enough to my liking yet. So I released the macOS version and put the computational cost on the end user and avoiding the need to support servers.
Sounds like I should make a native mobile version with the option to tweak parameters.