Single-tasking
One task at a time, with the rest actually out of sight.
Every productivity app agrees you should focus on one thing. Almost none of them are built so that you can. They highlight your top task and leave the other forty sitting underneath it, which means the decision you were trying to escape is still on the screen.
No account. No card.
What single-tasking actually means
Single-tasking is working on exactly one thing until it is done, or until you deliberately stop, with everything else out of view rather than merely further down. That last clause is the whole difference. Prioritising is a ranking exercise; single-tasking is a rendering decision.
It is easy to agree with in principle and almost impossible to practise in an app whose main screen is a list. The list is the product in most task managers, so hiding it is not a setting they can offer without becoming something else.
What multitasking really charges you
| Switching is not free | Part of your attention stays with the task you just left, so the first stretch after every switch runs at reduced quality. The cost is paid per switch, which is why a day full of small interruptions feels unproductive even though no single interruption was long. |
|---|---|
| Re-entry is the expensive part | The work is not lost when you switch away, it is lost when you come back and have to rebuild where you were. Long tasks with many exits pay that rebuild cost every time. |
| The list itself is a switch | Glancing at the other forty items is a context switch even when you do not act on it. You loaded them, compared them, and chose again. Keeping the list visible during focus work quietly charges you for that all session. |
Three things a real one-task-at-a-time app has to do
The other tasks have to be gone, not smaller
A highlighted top item with the rest of the list underneath is not single-tasking. The alternatives are still on screen, so the choice is still live and your attention keeps re-running it. Full screen, one task, nothing else rendered is the version that changes behaviour.
The next task has to already be decided
If finishing one thing drops you back into the pile to pick again, you get the freeze once per task instead of once per day. Single-tasking only holds if the order was settled beforehand. Deciding in advance is what makes the session a sequence rather than a series of standoffs.
Leaving has to cost something visible
Any focus mode you can slip out of unnoticed is a suggestion. It does not need to lock you in, and locking you in fails the first time something is genuinely on fire. It needs to be counted. Once exits are on the record, you can see whether the interruptions were real or whether backing out quietly became the habit.
How the Tunnel handles it
The Tunnel is Tunl Focus running a single task full screen with nothing else on it. No list underneath, no counter of what is waiting, no next-up strip. It also tracks the two things that end focus sessions: how often you back out, and how often you get interrupted. Those two numbers turn focus from a vague intention into a score you can beat.
The order it runs comes from the Reckoning, where every task already got a verdict, and from a set of scarce ranked slots that make it impossible to hold fifty priorities at once. That is requirement two handled before the session starts.
If you are here because you cannot get started at all, the fuller answer is on why task paralysis happens.
Common questions
What is single-tasking?
Single-tasking is working on exactly one thing until it is done or until you deliberately stop, with the rest of your work out of sight rather than merely deprioritised. The out-of-sight part is what separates it from a to-do list with a highlighted top item.
Is multitasking really that costly?
Switching between tasks carries a real cost: part of your attention stays with the previous task, so the first stretch after every switch runs at reduced quality. The cost is per switch, which is why a day of small interruptions can feel unproductive even when no single interruption was long.
How does Tunl Focus enforce one task at a time?
The Tunnel is full screen and shows one task with nothing else on it. There is no list underneath to glance at. It also counts the two things that actually break a session: how often you back out, and how often you get interrupted.
What if something urgent comes in mid-session?
You leave the tunnel. Tunl Focus does not lock you in. It records the exit, so over time you can see whether the interruptions were genuinely urgent or whether leaving became the habit.
One screen. One task. Nothing underneath.
No account. No card.