I've been enjoying Wallcat on my computer for at least a year now, it's refreshing to see a new wallpaper each morning and they are always of highest quality.
So today when I decided to customise my Android phone a bit, I thought it would be really nice to use wallpapers from wallcat. Before I had this idea, I was looking at themes that I might like to try and ended up buying KLWP for £3.99 and downloaded AHX presets to choose a theme from. It came with a nice wallpaper but that's when I had the idea to use wallcat. To do this you don't even need to pay for premium, you can create a new (or use a free) theme and use the code below to set the background.
$wg("https://beta.wall.cat/api/v1/channels/ea4KhWHUGE/image/" + df(yyyy-MM-dd) + "T00:00:00.000Z", json, ".payload.image.url.o")$
Instead of going the approach of finding a third-party app for wallcat, I used their API within KLWP so all I had to do was change a text field and enable the variable/code mode then added the code. It gets a JSON endpoint (which the ID of a specific image gallery channel) with today's date so it changes each day, then gets the url of the image from the result.