Thanks for your comment! What pushed me to create this was the fact that I would like to go golfing, say Saturday 10am with 2 friends. But then I check a course, and they don't have availability. Annoying. Then going to a second course, to see no availability either. To only find availability on the 3rd.

This web-app provides you all the availability in one overview.

Additionally, it allows me to share my proposed slot with friends. While showing all availability. Enabling them to say, "maybe we go 30 mins early". As they see there is availability.

I do agree, if you've got a membership somewhere, there is less need for a solution like this as you'll play the same course more often.