When i begin to use codeforces and be member in groups then i had sheets or contests whatever group managers add. Sometimes I forget and get busy with something so i miss my sheets suddenly, so are there any extensions help to configure your private groups contests and sheets. if there please mention them...

I wonder why codeforces don't send any notifications via email when one of contests where i registered in is about to start. i think this feature will be useful. It also can be applied on public / private contests.