I'll update this if I find more. For now, this seems to be a partial solution. It's a Gmail add on (except I don't use Gmail) that adds reminders. The options when setting reminders include cancelling it if someone replies, and to remind everyone in the thread. If you combine those two, it seems like — if you use Gmail's web client and have $23/month you're dying to get rid of — a decent way to add the feature. Source: over 1 year ago

Startup Stash • Tools and resources for entrepreneurs Integrations Directory • Directory of integrations for your no-code product. One Page Love • Find inspiration from one-page websites Do Things That Don’t Scale • Collection of unscalable startup hacks NoCodeList • Software for your projects Page Flows • User design flow inspiration Stackshare • Find software for your projects and business Side Hustle... Source: over 1 year ago

One of the things you will need to think about at this stage of the project lifecycle is the tools you will use to power your business. Startup Stash is a directory of tools (both free and paid-for) that you can utilize at the start of your business journey. In addition to that check our directory of tools, that we’ve checked and used during our startup journey. - Source: dev.to / about 2 years ago

"Startup Stash - A Curated Directory of Tools and Resources for Your Startup" https://startupstash.com. Source: almost 3 years ago

Also useful (but not a book): https://startupstash.com/. Source: about 3 years ago