Inkerval
For iPad and Apple Pencil

It remembers.
You do the math.

Inkerval is handwritten practice for university math. Solve real problems with your own hands, grade yourself honestly, and let a memory model decide what comes back tomorrow. What you learn stays learned.

Be first in when the doors open. No spam, ever.

The Inkerval Map: probability topics with visible levels, progress, and locks
A map, not a queue. Topics unlock as their foundations get solid.

How it works

Practice like it's your notebook.
Schedule like it's a science.

1.

Solve by hand

Real problems on paper that grows with your work. No multiple choice, no typing formulas.

2.

Grade honestly

Solved, shaky, or revisit. Your own verdict. Wrong answers never count against you; they just come back.

3.

Let it schedule

Spaced repetition tuned for mathematics, not flashcards. Open the app, clear the review deck, done.

What's inside

Two courses at launch. Written to be solved by hand.

Probability I

13 topics · hundreds of problems

Counting to the central limit theorem: conditional probability, Bayes, random variables, named distributions, joint distributions, inequalities and the LLN.

Differential Equations

10 topics · hundreds of problems

First order to systems: separable, exact, linear, oscillations, Laplace transforms, with modeling problems that start from words, not formulas.

What it costs

$29 a month. The first fourteen days are open.

Inkerval Full

$29 a month

Fourteen days of everything first, free.

  • Every course, every topic, all of it.
  • No free tier to outgrow, nothing extra to buy later.
  • Billed through the App Store. Cancel anytime.
  • Everything you've written stays yours either way.

One price, everything included. That felt more honest than three tiers and a lock on the good half.

The trial is the real app, not a preview. Fourteen days is long enough for the scheduling to actually come back around and show you what it does.

Nothing to pay yet. The waitlist is the only door open right now, and it's free.

No ads. No trackers.

Your work is yours. Your progress is real.