I also put my phone in a kSafe by Kitchen Safe for 20-30 minutes to break out of doomscrolling with no takebacks. I keep a wireless charger in the safe so it can charge while it's in there.
Another thing I realized by working at a job where I couldn't take my phone is that you can just go to the library and leave your phone at home.
You should do this regardless, no watch needed. The only phone notifications that should be turned on are ones that could be urgent. Phone calls, maybe text messages, alarms, and calendar reminders. No email, no social media, no stupid random apps telling you about some discount.
I just bought [product placeholder] and it has [features placeholder].
I am no longer distract by phon.
* Monitor your health and track your time to help stay focused.
* Disable as many spurious notification types on your phone as you can afford to do. My recommendation: All notifications that aren't live messages from individuals.
* Keep your phone out of immediate reach so that you break the habit one likely has of instinctively reaching for it to fill in moments of boredom.