I’m not talking about the NYT Cooking app, or the NYT games app — I guess I use the NYT suite of apps a lot??? — or Instagram or whatever. I’m talking about the app you use or love the most that other folks might not have heard of; it can be fun or insanely practical or silly or serious. Share the one weird app you’d never delete from your phone.

Photo by Ted Soqui/Corbis via Getty Images; yes, that is Kenny G showing Cindy Crawford something on his phone.