Availability planner: picking a time together, with no service in between
A planner a group uses to pick a date and time together. The organiser sends a file around; everyone marks in a grid when it suits them and sends a short code back. The organiser pastes the codes and gets a clear heatmap with the best options, including who can't make each moment. Much faster and clearer than a scheduling poll, and without login or advertising.
Everything sits in one HTML file. No account, no advertising, and no service that ever sees the data: it stays with the people themselves. Participants install nothing and share nothing except a line of text. I built the first version for my own association, for a meeting with many participants from different orchestras, and generalised it afterwards. Want it for your own group? Fill in your title, dates and times in the file and download your own version without a line of code.