Jon Cuthbert reviewedUnsplash Wallpapers for Mac (Official)Curated, HD desktop background photos from Unsplash.
 Recommended
Pros: 

Simplistic app that's easy to use.

Cons: 

I had a different background for 5 Spaces and it set the same image to every Space. I'd prefer it just set the image to the active Space.

Also, there could more more options like a keyword search.

Jon Cuthbert has used this product for one day.