Garmin Forerunner 10 might be a good choice for you. It is a straight forward GPS watch which gives walk/run intervals, pace, distance etc. In terms of walk/run intervals, it beeps at you and the screen says what you need to do e.g. Run for four minutes.
It is $129. I have attached a link below. You don't need a smart phone and data can be uploaded to a co purée.
https://buy.garmin.com/en-US/US/into-sports/running/forerunner-10/prod107143.html
Nope this helps.