These are Google Play Store free watchfaces which can be installed directly on any WearOS smartwatch
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Digital Informer
Vanishing Hour Watch
Wave
WES7 Onyx Watch
WES9 Sport Watch
Color Clock Watch
Concentric Pixel Watch
GBTQ (World Flags)
Pixel Minimal Watch
Radii
Scuba Diver Watch
Slate Watch
PhotoWear Classic Watch