Based on our record, Followup.cc seems to be more popular. It has been mentiond 1 time since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
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
FollowUpThen - The simplest way to schedule an email reminder
MEEFF - MEEFF – Make Global Friends app allows users to learn the Korean language and increase their knowledge about Korean culture by making friends from Korea and engaging in live chat with them.
Gmelius - Gmelius is the first collaboration platform designed for G Suite and your company's daily tools.
Online People-Meet New People - Online People-Meet New People app enables you to view the profile of strangers without letting them know to make new friends matching your personality and interests.
Right Inbox - Schedule Emails in Gmail To Be Sent Later
eChats - eChats is a social app by YBK creations that contains features to allow you to securely send text messages to your friends and family members without having to worry about any privacy threats.