Excalidraw is nice, not a grid of course, but mostly text on an infinite canvas and has alignment tools to make it neat. The other thing that popped into my he

Excalidraw is nice, not a grid of course, but mostly text on an infinite canvas and has alignment tools to make it neat. The other thing that popped into my head is maybe a Kanban tool (that would be a grid). You could do a quick paper prototype that easily with some postit notes on the wall to see if it works :).