Ask HN: What is the best browser “new tab” hack that keeps you productive?

Dabbling for a long time with ways of staying more productive, I always felt the "new tab" (in Chrome, Firefox, etc.) has a lot of potential to be the front page to a GTD hack that could simplify one's focus and help stay productive. Curious to hear what the community have been using the "new tab" for (e.g. todo lists, integrations with trello/ms todo/google tasks, integration with emails/calendars, pomodoro timers, etc.).