Marvel (Comics) API - Create awesome stuff with the world's greatest comic API
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
DC Universe - The DC Comics streaming service w/ original content
TaskPaper - Plain text to-do lists for Mac
Comixology Unlimited - Netflix for comics and graphics novels by Amazon
TickTick - TickTickis a cross-platform to-do list app & task manager helps you to get all things done and make life well organized.