I suffer from extreme time blindness and one apparent solution to this is to have a regular metronome like pulse - I would love an app for say a smart watch or something that did this with vibrations!

There is an iOS/watchOS metronome app literally called “Pulse” that provides haptic feedback. That might get you part of the way there

Managing time blindness has been a challenge, too.

I've discovered a helpful tool: the BlipBlip app on my Android device. This app allows for customizable settings such as selecting a ticking interval—in my case, a 15-minute reminder—and choosing from various ticking sounds, with my preference set to Casio.

Notably, it also enables the configuration of periods without ticking, particularly useful for nights or weekends.

The are plenty of other options but these are the ones I care about the most.

Hehe, I'm also working on a "metronome for my attention":

https://untested.sonnet.io/Things+to+support+my+own+well-bei...

hit me up via hello @ <website> or my newsletter on untested.sonnet.io and I'll message you when I have it.

That's an awesome list! And, yes, Pickel sounds like a tool I'd love to use. Can't wait to give it a try :)