We're trying to create workflow rules now.
We need very simple thing:
if new posibility is created with stage=Pending - there should be automaticly created task with immediate pop-up reminder
As you can see on attached screenshot - we can do everything except the last part "immediate pop-up reminder", because there is only a possibility to set fixed time in reminder setup for automaticly created task. What if the rule condition will be executed after that time - reminder will never pop-up?