Deadline Backsolve: Pace Plan

NOTE: The app interface is currently in Japanese only.
The App Store listing is in English, but the app itself is not yet localized.

When you realize you won't hit the deadline, what you actually
need is the answer to "so what do I change?"

Deadline Backsolve computes the shortfall and gives you concrete fixes:
"push the deadline 3 days", "add 45 minutes per working day",
"cut 4 pages". Real numbers, not a warning label.

■ Three inputs. Thirty seconds.
What, how much, by when. That's the whole setup.
Per-weekday hours and finer settings can wait until later.

■ You only look at today
The home screen says "Today: 8 pages." That's it.
No Gantt charts, no dense tables. Tap "+1 page" when you're done.

■ It follows your real week
One hour on weekdays, three on weekends? Your quota is distributed
by the time you actually have, not spread evenly into a plan
you were never going to keep.

■ It learns your real pace
It starts from an estimate, then switches to your measured
minutes-per-unit once you have logged enough work.
You never have to re-tune the estimate yourself.

■ Recovery plans, computed
- Switch to a later registered deadline (with hours gained)
- Extend the deadline by N days
- Add N minutes per working day
- Cut N units
- Finish each unit within N minutes
- Open up a day you had marked as rest
Tap any of them to apply it to the plan immediately.

■ A focus timer that survives a crash
It stores the start time and takes the difference, rather than
ticking every second. Close the app, crash the app, it keeps counting.
And it never plays a sound effect. Ever.

■ It does not go online
No account. No server. No ads. No tracking.
Your data lives on the device. Move it with a JSON export/import
when you change phones. There is no sync to corrupt.

■ One-time purchase. No add-ons.
Everything is unlocked at purchase. Unlimited projects and logs.
No subscription.

Works for comics, novels, illustration books and merch, but also
for article deliveries, reports and theses — anything with an
amount and a due date. Name the unit whatever you like.