Most todo apps don't really cater to the idea of a reusable list. Items effectively disappear once checked off, unless they're repeatable, in which case a new task is generated at the frequency you specify. There are lists of things that need doing repeatedly but not necessarily on a strict repeating schedule. Packing for travel and/or camping is a typical use case, as is a grocery list. You want a reusable prepopulated list of things you might need for any given trip.