Study school physics in one flow: concepts, worked examples, practice, review.
No account. No internet connection needed.
The app follows your device language —— English or Korean. Switch at any time;
your records carry over.
■ It traces the gap
If you keep missing conservation of mechanical energy and the real gap is in work
and kinetic energy, solving the same problem a hundred more times will not help.
This app gathers the concepts behind your wrong answers, walks back along the
prerequisites to the weakest one, and tells you where to start again.
A unit you reach this way opens its concepts and examples even when it is locked,
and it stays open.
Sometimes the gap is in math. When it is, the card says so plainly, so you know to
go back to your math course rather than read the physics again.
■ Constants are given inside the problem
Some textbooks take gravitational acceleration as 9.8 m/s², others as 10. If the
answer depends on which book you own, that is guessing, not study. Every problem
states the constants it needs: "Take g = 10 m/s²."
■ A grader that knows units
If the answer is 40 N, 0.04 kN is right too. Unit prefixes, conversions such as km/h
to m/s, and tolerance for decimal answers are all handled, and every grading rule is
covered by automated tests so that a right answer is never marked wrong.
Questions never say "answer in newtons". The answer box shows the unit.
Written answers accept the forms people actually write —— "valence band" or
"the valence band", "3" or "3 times".
■ Wrong answers come back when you are about to forget
Missed problems go into a review notebook and return after 1, 3, 7, 16 and 35 days.
Get one right and the interval grows; miss it again and it starts over.
You can mark why you missed it —— a slip in the math, an idea you misunderstood,
or a question you misread. A slip does not lower your mastery of the concept, and
it comes back in three days instead of one.
■ Formulas and diagrams are typeset, not pasted
No formula is an image. Fractions, radicals and vector arrows are drawn by
typesetting rules, so nothing blurs when you make the text larger.
Free-body diagrams, circuits, magnetic fields, energy levels and ray diagrams for
lenses —— 36 figures drawn from coordinates.
With VoiceOver, formulas are read aloud the way a teacher says them: "1 over 2",
"v squared", "the square root of 2 g h" —— and units by name, "meters per second
squared", not "m divided by s squared".
■ Concepts you can move
Six simulations —— resultant force, gravity and weight, elastic force, friction,
buoyancy, and how a net force changes motion. Drag the values and watch what
happens; it is quicker than reading about it.
■ What is inside
· Middle School Physics (Grades 7–9) —— forces and their effects, heat, light and
waves, electricity and magnetism, motion and energy (250 problems)
· Integrated Science: Physics (Grade 10) —— foundations of science, mechanical
systems, electrical properties of matter, energy conversion and power
generation (190 problems)
· Physics (Grade 11) —— force and equilibrium, momentum and mechanical energy, heat
and energy conversion, electric fields and circuits, magnetic fields and
electromagnetic induction, the wave nature of light and lenses, quanta and
matter (350 problems)
79 lessons, 790 problems, 99 concepts and a 133-entry glossary, all in English.
Every problem was written for this app.
The courses follow South Korea's 2022 national curriculum, including the limits its
commentary sets —— where it says a topic is to be treated qualitatively, we do not
ask for numbers.
■ Buying
One purchase per course. Not a subscription, never expires, Family Sharing on.
Without buying, the first two lessons of every chapter stay open —— 320 problems,
40% of the app.
■ Requirements
iOS 18.0 or later. No account. Works offline.
Your study records stay on your device and in your own iCloud.
Show more
