Sweet Goals
Ultra-intuitive, friendly and supportive, Sweet Goals is one of those apps that feels simple but has a huge host of features working in concert under the hood to make the experience of using it feel smooth as silk.
Sweet Goals includes full integration with Google Calendar, to make planning your to-dos even easier. Other integrations include Basecamp and Trello, making Sweet Goals a hub that can handle streams from whatever other checklists life (or your boss) requires you to use.