All the vibrating alarm clocks I could find do not sync with your phone, and have to be set manually. I thought about getting an Arduino, but then I will have to build the whole thing by myself. The only logical conclusion I could come up with is to get a programable vibrator. But most of them are either very expensive of look too much like a vibrator (sus).
This is the closest I got: https://www.amazon.com/dp/B09NNFPHXG https://www.amazon.com/dp/B0CD7FPFQ5?th=1
I use a Fitbit flex 2 for that purpose. I doubt they make that model anymore, but probably make something similar. The flex 2 is just a little lozenge-shaped thing that tracks movement, can vibrate, and has a few little lights. The app let’s you set alarms (you turn it off by tapping it). I also have mine set to vibrate when I get a text message or a phone call in case I’m someplace noisy and don’t hear it.
Hadn’t thought about using a sports watch, will try for sure. ty sir🫡
Look up the PineWatch. Its as affordable and Open Source as it gets
Love mine, but the motor is a little weak
It has the feature built in. You can get one for about $50 and it works well