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
How about a smart watch? I realise this is kind of specific but I have a Pixel 8 phone and a Pixel Watch 2. The alarms sync, and the vibration on my watch is enough to wake me up.
And honestly if they’re looking for affordability, I have a $25 mi fit (or at least that’s what it cost when I bought it 6 years ago) that has the same functionality. The app for it is shit, but it does the job.