Edit - And as for "why mobile-first", I wanted to make the app casual and approachable. You can take a photo of your teacup and have a cool low poly version of it in an instant. Or generate a pretty colourful wallpaper with one tap. But I'd love to build a desktop version too. Larger screen and finer control over the pointer would give some new possibilities.

Edit 2 - In case somebody didn't notice, you can generate a wallpaper for your desktop from the mobile app. Just choose a desktop option in the "Size" setting.