After show my project to the other participants (see the photo!) we started the discussion about how to improve the quality of my code and allow an easy collaboration with new members:
1) First, the new members have been added to the project. They can now discuss and try to understand the code, and I have started to solve their preliminary questions.
2) Then, the tracker system is used. New feature request have been added by some of the new members. These new requests include tickets related with licensing (for example, I have to add the licences header in each file, and also the LICENSE file), documentation, unitary tests, or templates.
3) Set milestones: in a couple of months I should have a Getting Started tutorial and a first release to be dowloaded and used.
Also, the code design has been also discussed. When you are developing for yourself all is easy, but when new collaborators start to wondering about how to start you realize that it is not as immediate as you think!
The presentation is here (is quite similar to this previous one):