Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.

Makerlog - Makerlog is the dead-simple task log that helps you stay productive and ship faster.

Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.

WIP.co - Work in progress. We are a community of makers who help each other ship product.

RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.

Indie Hackers - Connect with fellow entrepreneurs, developers, and bootstrappers who are sharing the strategies and revenue numbers behind their companies.