I would like to try it but on my smartwatch Google Play doesn't show the app, and if I try to install from PC browser, it let me to install just on my phone and my tablet, while the smartwatch is greyed out.
Downloaded it on my Moto G5 plus and on my Kospet Hope 4G standalone smartwatch. Works perfectly, even better than having to use Bluetooth for notification forwarding. With this app you get the notifications even if your device is powered off, or lost, or broken.
I was able to download it from the play store on my phone but had to sideload it onto my watch from a downloaded apk I got from apkfollow.com