Extract metadata from a .watchface

Hello, fellow developers! How would you approach .watchface file to extract it's metadata? I need to know in which version of the app the face was created, to prompt the user to update the app if necessary.

Looking at binary I suppose that a .watchface file consists of a PNG previews and JSON metadata and it all packed in one file somehow. Probably archived with gzip.

Extract metadata from a .watchface
 
 
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