Can you connect a smartwatch to any cell phone?

I've been wondering for a long time whether you can pair a smartwatch from a different brand than the mobile phone with your mobile phone?

For example a Huawei Watch GT2 with a Samsung Galaxy S9+? Or is that not possible and both things have to be of the same brand? (Samsung mobile phone + Samsung Smartwatch or Huawei mobile phone + Huawei Smartwatch)

Thank you in advance for the answers and I wish you a nice evening!

Most smartwatches can be connected to any mobile phone, but usually you need an app that should then also run on the mobile phone.

Why should you have to restrict that too?

Thank you for your answer!

Can you tell me what the name of this app is? And yes, I asked myself that too, my friend said that it was only possible with the same manufacturer and that confused me.

Every smart watch manufacturer has its own app…

Hmm, actually there are still two major operating systems for smartphones… Android, or iOS. MMn also share the SmartWatches in between, whereby the cooperation between products from the same manufacturer harmonizes best. But there are also cell phones that are not smartphones!

"… Whereby the cooperation between products from the same manufacturer harmonizes best…" does that mean there are minimal differences? Would you like to reveal which ones, for example?

Okay thank you very much

I've been using Pebble watches for years… Even since the original ones are no longer in operation. Although they're primarily designed for Android, they also go with Apple / iOS. However, the watch then digs into the system less, can't do so much, etc.