TopTracker - Beautiful, free time tracking
Free Invoicing Software - Free Invoicing Software provides the facility of online billing.
timeBuzzer - timeBuzzer enables freelancers and project-driven teams to track their time at the touch of a button, understand where their time goes and create reports with just a few clicks.
Teamleader - CRM, invoicing & project planning in a single tool for SME's
Cattr - Cattr is a free open-source self-hosted time tracker with desktop clients for windows, mac, linux.
Invoice Ninja - Invoice Ninja is a free, open-source solution for invoicing and billing customers.