OP: Hi guys, I'll do my best to reply to all comments posted here a bit later.
As it is now we're barely handling the flood of reviews. :) It's a good thing and very exciting but we had to scale up the number of heroku instances the second time in a row. So please bear with all the errors for a while, we're working on some issues esp. screenshot generation as it is not coping with the load.
Wow! We didn't expect an instant success like this. Thank you all for your contributions.