Unbend

Who it is for

A fabricator standing at a press brake. Not someone at a desk. They need a bend allowance or a flat blank length before they cut, and they need a flat pattern when the part is a cone, a cylinder or a segmented elbow. The answer has to arrive in seconds, on a phone, with gloves half on, and it has to be right, because the sheet is already cut once it is wrong.

The problem worth solving

Every competitor in this category ships the same screen: a technical drawing on top, and underneath it a column of unlabeled white input boxes. The iOS leader shows six boxes reading 10 5 45 20 10 90 with no labels at all. The user has to work out which box is which letter on the drawing above it. The other well-known product goes the opposite way and reproduces a physical shop calculator, forty-odd cryptic keys and all, which is unusable unless you already own the physical device.

So the drawing and the numbers are on the same screen and still have nothing to do with each other. That gap is the whole product.

The drawing is the form

Dimension values sit on the drawing itself as tappable chips. Tapping one raises a numeric keypad and the drawing redraws live as digits are typed; the active chip turns accent and the rest of the drawing drops to 55% opacity so there is never a question about which number you are changing.

• Fractional inches are first class: a 1/16 to 3/4 chip row, and true stacked fractions in the output rather than 7.0625. Every numeric value is set in mono so digits keep their width while someone is typing.
• The keypad carries previous and next in its header, so an experienced user walks every dimension on the part without dismissing it once. That is what replaces tabbing through form fields.
• Impossible geometry, a radius larger than the leg or a negative flat length, reaches the screen as one line that says what to change, not as "invalid input".

Stack

• React Native
• Expo
• TypeScript strict
• Unistyles
• Legend State
• MMKV
• react-native-svg
• Gorhom Bottom Sheet
• FlashList
• expo-print
• RevenueCat
• Vitest
• oxlint
• oxfmt