Chinese developer has made a Windows application that can help you design and create Amazfit watchfaces. It includes English localization (which is mostly good) Source: Made a dial to modify the tool – Huami Forums
Lots of new updates and an easier-to-follow layout are featured in the updated spreadsheet of apps that will run on, or with, the Amazfit Pace watch. Source: Amazfit PACE/Smartwatch compatible application list – Google Sheets