I made a tool for writers.
I loved the idea a plot grid but spreadsheets are too cumbersome. So I made a tool for myself and figured other authors might want it too, The Plot Grid takes a process many people do in Excel or Google Sheets and simplifies it into a purpose-built tool with a familiar form.
It's in beta now. It’s free and will always have a free version. Go play with it all you want. Anything you create is stored locally on your device.
theplotgrid.com