"Trump good" is not an effective business model either: https://parler.com/. Source: about 1 year ago

"No reasonable person believes that a Twitter clone just for conservatives is a viable business any more.". Source: about 1 year ago

Parler was shut down last week. See parler.com for the April 14 announcement. Source: about 1 year ago

See press release at https://parler.com/. Source: about 1 year ago

There's obviously nothing stopping Parler from moving their application to another platform as they've clearly done so. In fact, in software development it's highly encouraged to not have "vendor lock-in". There's also nothing forcing Apple, Google, and Amazon to allow applications in their app store. In the case of Android, at least, the "main" app store isn't the only way to get an application on the platform. Source: over 1 year ago

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