"Microsoft To Do" keeps my wife and I on the same page! We use it, increasingly, to help us plan and track routine tasks or specific projects around the house, through shared lists! Because "Microsoft To Do" lets you create customizable list, it can be adapted to almost any purpose or project; more specifically we share a, grocery/shopping list, chore list, meal planning list (including ingredients/recipe), a travel checklist, and a gift tracking lists. The "attach file" option is a big bonus!