Pocket has long been one of my essential apps, both on my phone and on my Mac. Everything I want to read I add to Pocket. Whenever I have a few moments to read and get inspired (like when I'm walking somewhere, on a bus/train/plane or waiting for someone) I turn to my Pocket app. This way I always have something interesting to read, while at the same time not interrupting my workflow when I first see an interesting link....
Wakeup Hero Feature Test: Hero Call » wakeup-hero: At Wakeup Hero we’re big fans of the Lean Startup methodology. As a result we test our assumptions before building a finished product. One of our assumptions is that a personal wakeup call (dubbed the Hero Call), is a nice and effective way for our users to make sure they get out of bed when they have something important to do (such as an exam, a meeting, air travel, etc)....
Other than the GTD methodology, the Pomodoro technique is my favorite productivity tool for actually getting stuff done. In short, it's a way to maximize the time where you're highly concentrated and productive and minimize both internal and external distractions. It helps you achieve this by time blocking (typically 25 min intervals) and a strict set of rules that help you keep focused. I've been using it for a couple of years now and it really complements GTD well....