Linux only: Free open-source utility Timer Applet makes GTD a breeze in Linux. Timer Applet sits unobtrusively in the system tray and displays the amount of time remaining for the current task. You can set (and save for future use) your own time limits, and when time expires, TA flashes and plays a WAV of your choosing. Timer Applet is the perfect companion for GTD and the 48 minute work spurt. It
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