Rated 5 out of 5 stars

Five stars absolutely, and I'd give it more if I could. I've been using ReminderFox for 12 years so far. I use it repeatedly every day. When it came time to migrate it from Firefox to Thunderbird, I did, and have continued without a hitch. It's basic to my planning of activities -- sometimes even years ahead -- and it also gives a valuable record of previous years. It's hard to imagine switching away from it, and I'm so pleased to know that it looks like I won't have to. My deep thanks to Günter and the others who have contributed to it.

This review is for a previous version of the add-on (2.1.6.3).  This user has other reviews of this add-on.