Sometimes cool stuff happens when you spell something wrong. The entire prompt was one word: avacadopunk. Give it a shot, curious what y'all get with that prompt.
Seamless textures are usually able to be tiled top, bottom, left and right, which this image is. So, if you were to use this with a fill tool in Affinity or Adobe products, it will seamlessly fill a shape.
This right here. The app is absolutely useless and unnecessary. Just don't use it.