I treasure a long-obsolete app from Foreflight, which was once available free, called Checklist Lite. I've managed to keep it on the various iPad upgrades, but if it ever went I would find myself wrestling with over-long generic paper checklists again. I've long been puzzled by the ommision of such a universally valuable and presumably simple add-on to Sky Demon, which I'm sure the majority of pilots would use and would save me personally from having to switch apps right at the point of take off. And the Sky Demon team would implement it very elegantly, I'm sure.