Are you on a Mac at home but a PC at work? In a cross-platform family? Plenty of to-do list apps work on one platform or another, but Todoist literally takes it up to 11. The service — even the free version — has apps that work with Android phones and tablets, the iPhone and iPad, Macs, PCs, Chrome, Firefox, Outlook and Thunderbird. (For those counting, the Web is also an option.) Users can organize their to-do lists by project, and completing one on one device should carry through to all the others. Other simple but important features such as offline access are also a plus. Paying a $29 per year fee will get you premium features such as the ability to add tasks over e-mail or receive reminders about certain to-dos. But the free version should work just fine for anyone just trying to manage their live across a whole universe of gadgets. Free, with $29/year premium option, for iOS, Android, Mac and PC.
— Hayley Tsukayama