I enjoy discovering new APIs to experiment with. In this case I came across Unsplash which is a source of high resolution images which are free to use. The developer API is well documented and it is a simple process to register an app to obtain an API key.
To skip ahead and see what I built using this API, see my Unsplash demo app on GitHub.
An opportunity to build an iOS app
An Image API service provides a nice basis for building an iOS app. It lends itself to working with table views, collection views, storage and many other iOS features. The following screenshots show what I was able to achieve.