Tie Tracker is a free and open source time tracking application. Its usage is meant to be simple and has the goal to lets you track work hours across projects. » Features Track your productivity and billable hours. * Simple work hours tracking * Assign time to clients and projects * Mark entries as billed » Reporting Yet not complicated but effective reporting. * Weekly work summary * Daily list of activities * Export open invoices to XLSX timesheets for Excel, LibreOffice, Numbers, etc.