If you are looking for a simple and minimalist to-do app with no fancy colors or unnecessary features, then you should give 2 Days app for iOS a try. 2 Days helps users in remembering their daily tasks with simplicity and efficiency. You don’t have to manage your tasks in categories, priorities, due date etc. You just have to create a simple task like you would on a piece of paper and you are done.
You can ask the app to remind you about any particular task at any given time, and it will notify you when the time has come. 2 Days app also features a Logbook, by using which you can keep track and reuse past tasks.
2 Days app fully supports iCloud, that means you can not only backup your tasks in the cloud, but also sync them with your other iOS devices.
2 Days is a universal app that is available in the App Store for $0.99 here