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

Raygun - Raygun gives developers meaningful insights into problems affecting their applications. Discover issues - Understand the problem - Fix things faster.

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

Snare - Snare is well known historically as a leader in the event log space.

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

Sentry.io - From error tracking to performance monitoring, developers can see what actually matters, solve quicker, and learn continuously about their applications - from the frontend to the backend.