Pomodoro, without the product
Four focus blocks, three short breaks, one long one. It runs itself, and there is nothing to sign up for.
The technique, briefly and honestly
Twenty-five minutes of work on one thing, five minutes off, four times, then a longer break. That is the whole method. It is often presented as a productivity system; it is really a commitment device. An open-ended intention to "work on the report this afternoon" is easy to defer. Twenty-five minutes starting now is not, because the cost of starting is bounded and visible.
The break matters as much as the block, and it is the part people skip. It exists so the next block is possible, not as a reward for the last one. Skipping breaks to chain blocks together produces the same fatigue as working straight through, which is what the technique was designed to avoid.
Why 25 is not sacred
Cirillo picked twenty-five minutes because it was the setting on his kitchen timer and it worked for him. For work with a long warm-up — writing, debugging, design — twenty-five minutes can end just as you get somewhere, and fifty or ninety is a better unit. The intervals are editable here for that reason. What matters is that the block has a defined end and the break actually happens.
Tracking the hours you are focusing for billing rather than for discipline? The hours calculator adds up sessions, breaks and billable totals for the day.