I was getting a 500 error every time I tried to load it. I’ve deleted my cookies and I can use it again. Thanks for the nudge!
However, even if PB is working, I would like to know about alternatives because it feels too clunky and usability is kind of poor.
My main use case for prediction book are private personal predictions and, secondarily, predictions for a small group, also private. I think using markets for the group predictions is also a good fit but AFAIK there are no private groups in manifold yet.