I guess I might have to bite the bit and hook up a phone app, but I would rather just look at a number. I had a po!ar chest strap 10 years ago. I think it had a wrist strap to look at. Guess that is obso!ete.
I had one of those and the chest strap would fail every few months- $30 to replace. Miserable. I'd be riding my bike uphill,, huffing and puffing, and it would be stuck on the heart rate it had measured down at the bottom of the hill,
All of these devices display your heart rate on the device itself. If your concern is that you don't want to be carrying your phone and looking at it every time you want to know your heart rate, that won't be an issue. The registration and phone process is meant to give you a place where you can look at trends, patterns, etc. over the long run and, I might add cynically, it gives the companies a way to bombard you with e-mails about their latest products and monetize your data. Use a spamcatcher e-mail address if you have one.