I do not have a special way of submitting feedback. What I do is that users write mail to ceoflightmussy@gmail.com or that people leave comments anywhere and it gets scooped up sometimes.

Each feedback is deciding how my projects will get shaped in the future. For example, I planned for Movie Scene Map to only show around 1000 locations, but because of feedback it shows 37 000 locations. Feedback gives me data to shape the projects better.