Ask HN: Service or tool where I can follow HN-ers?

Not by default, but you could cobble together something yourself pretty easily. You can see a given user's comments using something like:

https://news.ycombinator.com/threads?id=joering2

There's also an older thread that mentions somebody implementing something like this using the hnrss service, but I'm not sure if that's even still up or not.

https://news.ycombinator.com/item?id=25058236

You could setup an RSS reader with hnrss[0] to follow a particular user's posts and comments. This has been working pretty well for my own purposes. From there, the frequency of your updates should be configurable by whatever RSS reader you choose.

[0] https://hnrss.github.io/#user-feeds

example URL:

https://news.ycombinator.com/threads?id=joering2

https://news.ycombinator.com/threads?id=FOLLOWEDUSER

you can write a cron to step through a list of usernames ; pack each one into a URL; scrape it and do a sendmail