To purchase and run any of our apps, you must have an Wear OS 2.0 or greater device (Wear OS used to be called Android Wear, and Android Wear 2.0 watches should work fine, so long as they can connect to the Play Store to download the app). All faces are designed for a round screen, but they will run just fine on a square screen (though the corners will all be black).
Wear OS allows you to purchase watch faces directly from your watch device -- just search for "Emerald Sequoia" and you should find all of our apps, or search for the individual app name. Or you may find it easier to go the Google Play store in your browser via the links on this page, and click on the Install button; the app will then auto-install on your device so long as it is signed into the same account as your browser.
Note: If you have purchased the paid app Emerald Chronometer, you may find it convenient to uninstall the free app Emerald Chronometer FREE and any individual face apps you may have purchased, to avoid duplication in the face chooser.