SkySafari, the star chart app I use on my iPhone (and an all around find product, in my experience) has quite a few lists of objects that come with it. Unfortunately, none of them are a list for the Herschel 400. Never fear, though. You can import and export observing lists with SkySafari, and I’ve built one for the Herschel 400. There’s one object that’s left out because it’s a dubious duplicate of another object on the list, and the total objects on the list is a little over 400 because there’s a few objects on the Herschel 400 that have multiple NGC numbers that I included, but other than that it should be accurate.