Den — Vitark

Twenty-five minutes is a number someone made up

It came from a kitchen timer in the 1980s, and every Pomodoro app since has handed the same number to everybody. Den has no fixed interval. It starts from a way of working you pick, and then proposes the block length your own completed blocks support — showing you the counts it used.

That is a statement about arithmetic, not about you. Den measures nothing except the clock and your own taps.

Four ways of working

A starting point, never a box. Every setting underneath is adjustable on its own, and nothing you choose is stored as a fact about you.

Spark

for when starting is the hard part

Short blocks, cues that vary, a firm end.

Groove

for when stopping is the hard part

Long blocks, cues that never change, a warned and gradual end. The block is a floor, not a ceiling.

Weave

for when it is both

The same ritual every time, around work that changes.

Plain

just a timer

One length, one cue, nothing learned. All of the above switched off.

The cue arrives

Every other feature is worthless if a cue is silently dropped. On Android Den runs a foreground service carrying a live countdown, and sets an exact alarm beside it, so the cue survives Doze and a killed process.

Prove it with the screen off

Den has a self-test: lock your phone and put it down, and it will cue you in sixty seconds. Pass or fail is reported plainly, and a failure points at the setting responsible — including the vendor-specific ones that stop background apps on some phones.

Verified on a Pixel 10 Pro XL: the cue fired through Doze with the screen locked.

More than one thing at once

Threads — commitments of time, like an hour a day of something. Den compares what they ask for against the hours you have actually recorded, and tells you the arithmetic.
Hard dates — a return, a flight. Den works out the day it has to start, from the hours left over once your threads have taken theirs.
Coming up — a conference with things that must happen first. Some of those have their own earlier dates, and Den says so, because something that fits overall can still be at risk.

There is no ordering, no percent complete and no deadline on a thread. A thread cannot be late.

Your data stays yours

No account and no Vitark server. Nothing is uploaded anywhere by default.
Export is plain files. Ordinary JSON with documented field names, a spreadsheet-ready table, and a SHA-256 manifest so you can check nothing has been altered. If Den disappears tomorrow the folder is still readable in a text editor.
Sync is optional and encrypted. Turn it on and your list travels between your own devices through relays you choose, which hold something they cannot read.
Your settings never travel. How you have Den set up stays on the device, whatever else you switch on.

What Den cannot do

The app asks for no permission to see which other apps you run, no location, no camera and no microphone. It cannot know what else is on your screen, and it does not ask.

What it deliberately is not

No streaks, points, levels or scores. Nothing accumulates, so there is never a run to protect.
No due-date badges and no red. The word overdue appears nowhere.
Not a website blocker. Nothing is ever locked away from you.
Not a task manager. Three states and a shortlist capped at three.
Not a coach. No encouragement, no personified assistant.
Not a medical device. Den does not diagnose, screen, treat or monitor anything, contains no questionnaire or assessment of any kind, and makes no claim about any condition.

Where it is up to

In development, and not yet released. Android and the web both build today; the iOS build compiles and runs in the simulator. Part of the Vitark suite, alongside Still and Train.

The web version is a working surface for your list. Cues need the phone — browsers cannot wake you.