clockodo - Clockodo is a time tracking software for small and medium-sized companies.

Task Coach - Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists.

TimeTrackApp - TimeTrack Enterprise is ideal for collaboration in teams and companies. At the same time the freelancer version was designed for individuals who want keep track of their projects.

Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.

Sawayo.de - The business owner tool which saves hundreds of hours spend on non-value-adding tasks like employee time tracking, compliance research and workflow implementation (available in German).

Strikethru - Strikethru is a kind of to-do list notebook for managing work lists and staying updated with the important tasks.