Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
UI Garage - Specific mobile and web design patterns for your inspiration
Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.
Muzli - UI/UX and Design Inspiration Chrome Extension
EssentialPIM - EssentialPIM is a free Personal Information Manager that keeps up with the times and lets you manage appointments, tasks, notes, contacts, password entries and email messages across multiple devices and cloud applications.
Design Hunt - Curated design inspiration for everyone