>... my wife's sourdough starter living on the counter and getting fed when she remembers. The app reminds her; she ignores the app; the starter survives anyway because sourdough is remarkably forgiving.

That's so great about sourdough starter, you don't have to babysit it at all. We'll, that is, once I figured out that I should ignore the "hydration hydration hydration" and "add blah percentage water and 1.618034 grams of flour" advice. Instead, I just add lots (yes, that's a measure, like pinch and scoop) of fresh flour to my starter and just add water until it's a gooey sticky mess. Leave it alone and it'll do its thing.