MacStories:

Watchsmith, the latest app from David Smith, was birthed from the inability to create third-party watch faces on the Apple Watch. As Smith has previously explained, while third-party faces may never be possible, several first-party faces already offer significant room for customization. The Infograph face, for example, contains eight different complication slots; if a rich array of third-party complications were available, you could build a highly customized watch face using the existing faces provided by Apple.

Watchsmith exists to provide that rich set of complications. The app offers 37 types of complications, each adaptable to different watch faces and complication slots, and all fully customizable so they can look exactly the way you prefer. Additionally, Watchsmith offers scheduling functionality to cause different complications to appear on your Watch at different times throughout the day.

This is a clever hack to get around Apple’s prohibition on third-party complications.