TaskPaper - Plain text to-do lists for Mac
Makerlog - Makerlog is the dead-simple task log that helps you stay productive and ship faster.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
WIP.co - Work in progress. We are a community of makers who help each other ship product.
Microsoft To-Do - Task management tool
Indie Hackers - Connect with fellow entrepreneurs, developers, and bootstrappers who are sharing the strategies and revenue numbers behind their companies.