Rated 5 out of 5 stars
Yes, probably there was something special which pushed me/us to work on Reminderfox .. for years with fun and hearing lots of positive comments. Also the time is getting harder to follow the massive changes caused by Mozillas move to new technologies and removing old, mature technics, parts they don't need anymore for Firefox Quantum etc..
There will be a new Reminderfox version soon and it had to follow those mentioned changes. Not for every of the Mozilla changes we are able to implement a sufficient solution to keep all of our features, the statusbar seems to be one of that .. and we are sorry about that.
But for the statusbar Reminderfox feature there are some possibilities to bring it back (partially), pending on the system (Firefox, Thunderbird or Seamonkey) and their version. We will post about that in our Forum .
Please remember Reminderfox is an opensource project, the current development status can be found on GIT  and everyone is invited to join and contribute to it. We would be happy to get help!
Günter / Reminderfox Team
 Reminderfox Forum: https://groups.google.com/forum/#!forum/reminderfox
 Github: https://github.com/neandr/reminderfox