The company unveiled the new suggestions in a blog post, citing a desire to "improve the quality of apps for Wear OS and their presentation in the Google Play Store".
The new set of guidelines comes into effect on 31 August - presumably after we've seen the Samsung Galaxy Watch 6 arrive, and potentially Wear OS 4.0 - and also means developers only have a few months to make their apps compliant.
If they don't, Google says, they even risk being hidden from searches on the Play store.
So, what will actually change with the new guidelines?
Well, aside from making developers aim to make Wear OS apps compatible with Android 11 (and above) in order to maintain safety and security standards, there are a few key visual changes that you can expect to see in the latter half of this year.
One of the more interesting is the decision to enforce all-black backgrounds on third-party apps, as shown above.
As we've seen with the Google Pixel Watch, doing so means the bezel blends in with the display across the UI, and it's likely it also has a positive impact on battery efficiency.
Viewing ongoing workouts is also set to become a bit clearer, with Google demanding apps soon show an icon when an activity is being tracked.
Per the guidelines, apps must also show ongoing activity on a Tile (if the app is chosen to appear in the Tile carousel), and show live details in the app launcher, as well.
A basic feature that we've seen present in the Apple Watch for many years - the time being shown in the same spot across the whole UI - will be coming to Wear OS, too.
Google notes that it must be shown at the top of the display, though it doesn't need to be present in the likes of confirmation screens (and others on which users will only spend a couple of seconds).
All in all, these obviously aren't game-changing additions to the platform, but it does once again highlight the attention Google is finally giving Wear OS.
And as we've seen with other smartwatch operating systems, these small changes can also add up to make a big difference to the overall feel.
The only question that really remains is how quickly third-party app developers will get up to speed and roll out updates.
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