I'm looking for any suggestions for smartwatch that it similar like Google Pixel Phones with GrapheneOS. Is there such a thing?
Notifications, media control, minor navigation aids, some heart rate stuff (they've linked some papers for their algorithm which I think is cool cause now we can discuss the validity of said algorithm for heart rate monitoring) and most importantly 1024 (the game)
And 1 week (approx) of battery life
Similar to what most smartwatches can: measure heartbeat, show notifications and answer calls from your smartphone, flashlight (by showing white write screen), show weather, etc.
You can't actually take calls on the PT, you can use it to pick up your phone.
It's pretty barebones, but I like it for the price that it costs and the freedom it gives.
There's AsteroidOS but I couldn't find any of the supported watches (all quite old IIRC) at a reasonable price.
Gadgetbridge with some proprietary watch is fine privacy-wise (I had an Amazfit GTR3 pro, I needed to register an account with the Zapp app and use it once, but then uninstalled it once I got the required password and used Gadgetbridge exclusively).
Bangle and the Pine Watch are low-res and IMHO quite ugly compared to alternatives from big brands.
Gatgetbridge (your link) has a breakdown of devices they support https://gadgetbridge.org/gadgets/ . You can click through the vendors to find devices which are both "highly supported" and "no vendor-pair". Meaning most/all the features work without any reliance on the vendor app.
As for the similarity you are asking about with pixel->GrapheneOS, there are very few watches that can run an alternative open source firmware or operating systems apart from the ones that are already open source, like bangle.js, pinetime, etc. Wearables are even more specialized than phones, they require specialized code designed specifically for them and would likely require pretty extreme effort to reverse-engineer.
I use a pebble 2 HR with gadgetbridge but the watch it self runs the old pebble firmware which gadgetbridge talks to. This is fine for me, but if you are looking for a more modern watch you may have to make some compromises.
PineTime is everything Foss but is only for simple stuff (notifications, time, media control, pedometer, stop watch.) Had mine for a couple of years now and it still gets updated 👍
Old Pebble if you can find a working one that someone will part with.
if it existed I would be using it. Garmin is the next closest not total crap "smart" watch.
I only know of the Pine Time, however they warn that their watch OS is community driven and under active development.
I don't have one myself as I don't like jewelry.
However you can gather a lot based on the release history in the Infinitime wiki
Idk if it can be called a smartwatch, but I just found out about the sensor watch, and now I really want one. Basically a hackable Casio f-91w
If it had an accelerometer and Bluetooth I'd have it already.
I'm using an Amazfit bip watch. Is full supported from gadgetbridge.
I'm presently using the huawei watch fit 3 on gadgetbridge nightly, which I am enjoying but it definitely has its quirks.
They're also adding the Garmin watches, which are well known for their activity tracking.
