@ivo
Hi Ivo,
I was just wondering if you've managed to make any progress on this project? I recently created https://www.extremesportsearch.com/ which is a crowd-sourced project for extreme sport locations around the world. I can sympathise how hard it is to get users to collaborate, and I think that your creative commons approach is probably favoured by most.
My understanding is that you want a small web application and database residing on your servers, with all of the code open-source and hosted on GitHub. I'm very happy to collaborate with you on this and can easily create an application for you. I'm based in the UK and available to talk next week if you're interested.
All the best,
Paul

as kitesurfer - i used the historical data to plan my surfing-trips worldwide. To see what have been dominant winds during a specific time of year on a spot.
i wouldn't mind paying for the feature.