We present you a web application built for Basel Zoo (Switzerland) by André Bender (Swiss Web Factory), known in our community as @swf.
Here's the description he kindly provided:
For Basel Zoo, we implemented a competition application that enables the flexible creation of competitions, such as a digital Advent calendar. The competitions are controlled via our CMS and allow complex question / answer combinations. Various display options are available for the competitions. An automatic newsletter registration with a double opt-in process is also implemented in the system.